feat: add cloudsql-connectivity team as cloud_sql/ reviewer (#837)

Author: loeng2023

.github/CODEOWNERS

@@ -7,7 +7,7 @@
 /build/                       @terraform-google-modules/terraform-samples-git-admins @terraform-google-modules/cft-admins @terraform-google-modules/cloud-samples-infra
 
 /bigquery/                    @terraform-google-modules/bigquery-terraform-swe @terraform-google-modules/terraform-samples-reviewers
-/cloud_sql/                   @terraform-google-modules/terraform-samples-reviewers
+/cloud_sql/                   @terraform-google-modules/cloudsql-connectivity @terraform-google-modules/terraform-samples-reviewers
 /cloudvpn/                    @terraform-google-modules/dee-infra @terraform-google-modules/terraform-samples-reviewers
 /composer/                    @terraform-google-modules/cloud-dpes-composer @terraform-google-modules/terraform-samples-reviewers
 /compute/                     @terraform-google-modules/dee-infra @terraform-google-modules/terraform-samples-reviewers