No integration test coverage for the GCP C# and Java examples #3016

scripts/changed-examples.sh derives a <Cloud><Lang> test set from each changed file's top-level directory, then drops any set that has no TestAcc<Set> runner in misc/test. The only GCP runners are TestAccGcpGo*, TestAccGcpHcl*, TestAccGcpPy* and TestAccGcpTs*.

So gcp-cs-functions, gcp-cs-gke and gcp-java-gke-hello-world can never be selected, on a PR or on the nightly sweep. A PR that changes only those three runs no integration job at all, and reports green.

This is not limited to GCP. all_test_sets() is the single source both workflows read, and a set listed there with no matching runner is worse than an absent one: go test --run= on a set with no runner matches nothing and exits 0, so the job reports success having tested nothing.

Concrete instance: #3002 edits all three of those examples. dotnet build and mvn compile are the only evidence they work.

Related to #2993.