Remove unused ProjectDiagnosticAnalyzer (dotnet#8304)

* Remove unused ProjectDiagnosticAnalyzer

* Update proj file

Author: tmat

Diagnostics/ProjectDiagnosticAnalyzer.fs

@@ -144,6 +144,10 @@
     <Compile Include="Debugging\LanguageDebugInfoService.fs" />
     <Compile Include="Debugging\BreakpointSpanResolver.fs" />
     <None Include="Debugging\BreakpointResolutionService.fs" />
+    <Compile Include="Diagnostics\DocumentDiagnosticAnalyzer.fs" />
+    <Compile Include="Diagnostics\SimplifyNameDiagnosticAnalyzer.fs" />
+    <Compile Include="Diagnostics\UnusedDeclarationsAnalyzer.fs" />
+    <Compile Include="Diagnostics\UnusedOpensDiagnosticAnalyzer.fs" />
     <Compile Include="DocComments\XMLDocumentation.fs" />
     <Compile Include="Completion\GlyphHelper.fs" />
     <Compile Include="Completion\CompletionUtils.fs" />