chore: bump Microsoft.Extensions.Options from 7.0.1 to 8.0.0 in /src

Bumps [Microsoft.Extensions.Options](https://github.com/dotnet/runtime) from 7.0.1 to 8.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v7.0.1...v8.0.0)

---
updated-dependencies:
- dependency-name: Microsoft.Extensions.Options
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

src/UnityNuGet/UnityNuGet.csproj

@@ -23,7 +23,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Options" Version="7.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0" />
     <PackageReference Include="NuGet.PackageManagement" Version="6.7.0" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0" />
     <PackageReference Include="NUglify" Version="1.21.0" />