Cleanup

- Drop the eight Rider "Shard N" run configurations. They drove the old
  VSTest host (`dotnet test --settings ... --logger trx`) against
  per-shard .runsettings files that no longer exist.
- Add .editorconfig overrides so the two test csproj files and
  Directory.Build.targets keep their 2-space indentation.

Author: Mackamuir

.editorconfig

@@ -287,3 +287,8 @@ dotnet_naming_style.begin_s_.required_prefix = s_
 dotnet_naming_style.begin_s_.required_suffix =
 dotnet_naming_style.begin_s_.word_separator =
 dotnet_naming_style.begin_s_.capitalization = camel_case
+
+
+# Overrides
+[{**/{Content.Tests.csproj,Content.IntegrationTests.csproj},Directory.Build.targets}]
+indent_size = 2