Bump Roslynator.Analyzers from 4.6.2 to 4.12.1 in /src

Bumps [Roslynator.Analyzers](https://github.com/dotnet/roslynator) from 4.6.2 to 4.12.1.
- [Release notes](https://github.com/dotnet/roslynator/releases)
- [Changelog](https://github.com/dotnet/roslynator/blob/main/ChangeLog.md)
- [Commits](dotnet/roslynator@v4.6.2...v4.12.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/Directory.Build.props

@@ -27,7 +27,7 @@
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
-        <PackageReference Include="Roslynator.Analyzers" Version="4.6.2">
+        <PackageReference Include="Roslynator.Analyzers" Version="4.12.1">
             <PrivateAssets>All</PrivateAssets>
         </PackageReference>
     </ItemGroup>