Bump System.Resources.Extensions from 7.0.0 to 8.0.0

Bumps [System.Resources.Extensions](https://github.com/dotnet/runtime) from 7.0.0 to 8.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v7.0.0...v8.0.0)

---
updated-dependencies:
- dependency-name: System.Resources.Extensions
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

Gu.Wpf.UiAutomation.Tests/Gu.Wpf.UiAutomation.Tests.csproj

@@ -17,7 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Resources.Extensions" Version="7.0.0" PrivateAssets="all" />
+    <PackageReference Include="System.Resources.Extensions" Version="8.0.0" PrivateAssets="all" />
     <PackageReference Include="Gu.Analyzers" Version="2.0.3" PrivateAssets="all" />
     <PackageReference Include="IDisposableAnalyzers" Version="4.0.7" PrivateAssets="all" />
     <PackageReference Include="Microsoft.CodeAnalysis.NetAnalyzers" Version="7.0.4" PrivateAssets="all" />