fix: Use correct property to specify target framework in Coco.csproj (#1831)

`net5.0` is a Target Framework Moniker, which can be used in `TargetFramework` but
not `TargetFrameworkVersion`.  This caused errors with some versions of MSBuild
and Omnisharp:

    c:\Users\user\git\dafny\third_party\Coco\src\Coco.csproj: Microsoft.Build.Exceptions.InvalidProjectFileException: The expression "[Microsoft.Build.Utilities.ToolLocationHelper]::GetPathToStandardLibraries(.NETFramework, net5.0, '', AnyCPU, '', '')" cannot be evaluated. Input string was not in a correct format.  c:\Users\user\.emacs.d\.cache\lsp\omnisharp-roslyn\latest\omnisharp-roslyn\.msbuild\Current\Bin\Microsoft.Common.CurrentVersion.targets
       at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args)
       at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject[T1,T2](IElementLocation elementLocation, String resourceName, T1 arg0, T2 arg1)
       at Microsoft.Build.Evaluation.Expander`2.Function`1.Execute(Object objectInstance, IPropertyProvider`1 properties, ExpanderOptions options, IElementLocation elementLocation)
       at Microsoft.Build.Evaluation.Expander`2.PropertyExpander`1.ExpandPropertyBody(String propertyBody, Object propertyValue, IPropertyProvider`1 properties, ExpanderOptions options, IElementLocation elementLocation, UsedUninitializedProperties usedUninitializedProperties, IFileSystem fileSystem)
       at Microsoft.Build.Evaluation.Expander`2.PropertyExpander`1.ExpandPropertiesLeaveTypedAndEscaped(String expression, IPropertyProvider`1 properties, ExpanderOptions options, IElementLocation elementLocation, UsedUninitializedProperties usedUninitializedProperties, IFileSystem fileSystem)
       at Microsoft.Build.Evaluation.Expander`2.PropertyExpander`1.ExpandPropertiesLeaveEscaped(String expression, IPropertyProvider`1 properties, ExpanderOptions options, IElementLocation elementLocation, UsedUninitializedProperties usedUninitializedProperties, IFileSystem fileSystem)
       at Microsoft.Build.Evaluation.Expander`2.ExpandIntoStringLeaveEscaped(String expression, ExpanderOptions options, IElementLocation elementLocation)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluatePropertyElement(ProjectPropertyElement propertyElement)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluatePropertyGroupElement(ProjectPropertyGroupElement propertyGroupElement)
       at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluateImportElement(String directoryOfImportingFile, ProjectImportElement importElement)
       at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluateImportElement(String directoryOfImportingFile, ProjectImportElement importElement)
       at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluateImportElement(String directoryOfImportingFile, ProjectImportElement importElement)
       at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
       at Microsoft.Build.Evaluation.Evaluator`4.EvaluateImportElement(String directoryOfImportingFile, ProjectImportElement importElement)
       at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
       at Microsoft.Build.Evaluation.Evaluator`4.Evaluate()
       at Microsoft.Build.Evaluation.Evaluator`4.Evaluate(IEvaluatorData`4 data, ProjectRootElement root, ProjectLoadSettings loadSettings, Int32 maxNodeCount, PropertyDictionary`1 environmentProperties, ILoggingService loggingService, IItemFactory`2 itemFactory, IToolsetProvider toolsetProvider, ProjectRootElementCacheBase projectRootElementCache, BuildEventContext buildEventContext, ISdkResolverService sdkResolverService, Int32 submissionId, EvaluationContext evaluationContext, Boolean interactive)
       at Microsoft.Build.Evaluation.Project.ProjectImpl.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
       at Microsoft.Build.Evaluation.Project.ProjectImpl.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
       at Microsoft.Build.Evaluation.Project.ProjectImpl.ReevaluateIfNecessary(EvaluationContext evaluationContext)
       at Microsoft.Build.Evaluation.Project.ProjectImpl.Initialize(IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
       at Microsoft.Build.Evaluation.Project..ctor(String projectFile, IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
       at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary`2 globalProperties, String toolsVersion)
       at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore(String filePath, IReadOnlyDictionary`2 projectConfigurationsInSolution) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectLoader.cs:line 157
       at OmniSharp.MSBuild.ProjectLoader.BuildProject(String filePath, IReadOnlyDictionary`2 configurationsInSolution) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectLoader.cs:line 75
       at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load(String filePath, ProjectIdInfo projectIdInfo, ProjectLoader loader, Guid sessionId, DotNetInfo dotNetInfo) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectFile\ProjectFileInfo.cs:line 117
       at OmniSharp.MSBuild.ProjectManager.<>c__DisplayClass31_0.<LoadProject>b__0() in D:\a\1\s\src\OmniSharp.MSBuild\ProjectManager.cs:line 304
       at OmniSharp.MSBuild.ProjectManager.LoadOrReloadProject(String projectFilePath, Func`1 loader) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectManager.cs:line 315

Co-authored-by: Mikaël Mayer <[email protected]>

Author: cpitclaudel

third_party/Coco/src/Coco.csproj

@@ -8,7 +8,7 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>Coco</RootNamespace>
     <AssemblyName>Coco</AssemblyName>
-    <TargetFrameworkVersion>net5.0</TargetFrameworkVersion>
+    <TargetFramework>net5.0</TargetFramework>
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
   </PropertyGroup>