Prefer a domain-qualified finalizer name to avoid accidental conflicts with other finalizer writers (chains.tekton.dev)

[jsoref]

https://tekton-releases.appspot.com/build/tekton-prow/pr-logs/pull/tektoncd_chains/1148/pull-tekton-chains-integration-tests/1807738097719316480/

    {"level":"warn","ts":"2024-07-01T11:51:34.769Z","logger":"watcher","caller":"logging/warning_handler.go:32","msg":"API Warning: metadata.finalizers: \"chains.tekton.dev\": prefer a domain-qualified finalizer name to avoid accidental conflicts with other finalizer writers","commit":"2f98765-dirty"}

https://github.com/tektoncd/chains/blob/cd9106b8d3af008f62ecb5b1a050fa19b079d1c8/pkg/reconciler/taskrun/controller.go#L89

The theoretical fix for this is:

- FinalizerName:     "chains.tekton.dev", 
+ FinalizerName:     "chains.tekton.dev/finalizer", 

But, in practice, if your objects are long lived, you will want to include migration code so that old finalizer values are accepted/handled.