pub const META_CACHE_KEY: &str = "cache_key";Expand description
Marks a Step that calls actions/cache (or actions/cache/save /
actions/cache/restore). The cell value is the raw key: input from
the step’s with: block. Consumed by pr_specific_cache_key_in_default_branch_consumer
to detect PR-derived cache keys (head_ref, head.ref, actor) that a
default-branch run can later restore — classic cache poisoning.