Bump NUnit.Analyzers from 4.8.1 to 4.9.0

---
updated-dependencies:
- dependency-name: NUnit.Analyzers
  dependency-version: 4.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

stdc.Tests/stdc.Tests.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="nunit" Version="4.3.2" />
-    <PackageReference Include="NUnit.Analyzers" Version="4.8.1">
+    <PackageReference Include="NUnit.Analyzers" Version="4.9.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>