fix: Builds failing intermittently on Windows

[jamescrosswell]

Resolves #4091:

• Windows builds are failing intermittently on CI #4091

Explanation

Previously we had this build target in Sentry.Android.AssemblyReader.Tests.csproj:

sentry-dotnet/test/Sentry.Android.AssemblyReader.Tests/Sentry.Android.AssemblyReader.Tests.csproj

Lines 19 to 24 in a04a10a

	<!-- Build the Android test app in various configurations during the build of this test project. -->
	<Target Name="BuildTestAPKs" BeforeTargets="DispatchToInnerBuilds;BeforeBuild" Condition="'$(TargetPlatformIdentifier)' != 'android'">
	<MSBuild Projects="..\AndroidTestApp\AndroidTestApp.csproj" Targets="Restore" />
	<MSBuild Projects="$(MSBuildProjectFile)" Targets="_InnerBuildTestAPKs" Properties="TargetFramework=net8.0-android" />
	<MSBuild Projects="$(MSBuildProjectFile)" Targets="_InnerBuildTestAPKs" Properties="TargetFramework=net9.0-android" />
	</Target>

It was building for both the net8.0-android and net9.0-android targets... however it also gets called for both the net8.0 and net9.0 TFMs for Sentry.Android.AssemblyReader.Tests.csproj. So essentially it's duplicated and sometimes on Windows that results in two instances of the task trying to write to the same files - leading to a permission denied error.

#skip-changelog