Optionally suppress the warning about non-existing directory to be cached

Situation: actions/cache is reused by a higher-level action that caches certain directory using it. This directory may or may not exist by the end of a workflow, and it not existing is not an error.

However, actions/cache then prints the following in the output:

Warning: Path Validation Error: Path(s) specified in the action for caching do(es) not exist, hence no cache is being saved.

While not a major concern, it still would be nice to avoid warnings in normal situations. As far as I see from the source code, there is no way to suppress this message. Can you add one so that outer action (or workflow) can decide between "such situation shouldn't happen, issue a warning" (as now) and "such situation is normal and completely possible, simply ignore it"?

Start by tracing the path-validation warning in the actions/cache source; the issue does not name a file or test. Determine how an outer action or workflow could opt out of this warning while preserving the current behavior by default, then verify that missing cache paths no longer produce the warning when suppression is enabled.