Update dotnet monorepo (major) (#1516)

* Update dotnet monorepo

* Fix package downgrade warning

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Andrew Arnott <andrew.arnott@microsoft.com>

Author: renovate[bot]

Directory.Packages.props

@@ -14,7 +14,7 @@
     <PackageVersion Include="DNNE" Version="2.0.8" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.1" />
     <PackageVersion Include="Microsoft.CodeAnalysis" Version="$(CodeAnalysisVersion)" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="4.14.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="$(CodeAnalysisVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="$(CodeAnalysisVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="$(CodefixTestingVersion)" />

test/Directory.Packages.props

@@ -3,12 +3,13 @@
   <Import Project="$([MSBuild]::GetPathOfFileAbove($(MSBuildThisFile), $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
-    <CodeAnalysisVersionForTests>4.13.0</CodeAnalysisVersionForTests>
+    <CodeAnalysisVersionForTests>5.0.0</CodeAnalysisVersionForTests>
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Update="Microsoft.CodeAnalysis" Version="$(CodeAnalysisVersionForTests)" />
     <PackageVersion Update="Microsoft.CodeAnalysis.Common" Version="$(CodeAnalysisVersionForTests)" />
     <PackageVersion Update="Microsoft.CodeAnalysis.CSharp" Version="$(CodeAnalysisVersionForTests)" />
     <PackageVersion Update="Microsoft.CodeAnalysis.VisualBasic" Version="$(CodeAnalysisVersionForTests)" />
+    <PackageVersion Update="System.Collections.Immutable" Version="9.0.13" />
   </ItemGroup>
 </Project>