[release/9.0] Readd DiagnosticSource to KestrelServerImpl#60202

wtgodbe merged 2 commits intorelease/9.0dotnet/aspnetcore:release/9.0from

backport/pr-60129-to-release/9.0dotnet/aspnetcore:backport/pr-60129-to-release/9.0Copy head branch name to clipboard