build(deps): bump Microsoft.Extensions.Configuration in /src

Bumps [Microsoft.Extensions.Configuration](https://github.com/dotnet/runtime) from 8.0.0 to 9.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v8.0.0...v9.0.0)

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

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

src/Fluss.PostgreSQL.IntegrationTest/Fluss.PostgreSQL.IntegrationTest.csproj

@@ -9,7 +9,7 @@
 
     <ItemGroup>
         <PackageReference Include="coverlet.collector" Version="6.0.2"/>
-        <PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0"/>
+        <PackageReference Include="Microsoft.Extensions.Configuration" Version="9.0.0"/>
         <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="8.0.0"/>
         <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.0"/>
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0"/>