Enable code cov to include net9.0 result files (#3774)

Author: cheenamalhotra

eng/pipelines/dotnet-sqlclient-ci-core.yml

@@ -56,7 +56,7 @@ parameters:
 - name: codeCovTargetFrameworks
   displayName: 'Code Coverage Target Frameworks'
   type: object
-  default: [net462, net8.0]
+  default: [net462, net8.0, net9.0]
 
 - name: buildType
   displayName: 'Build Type'