flaky: container-safe flaky-filter + record-results; add stale (max adoptability)

[kei-nan]

Enhances the shared repo so consumers can fully adopt the flaky-test tooling
(and drop their local flaky_db.py), plus re-adds stale as opt-in.

Why

The flaky composite actions are used inside container test jobs (RediSearch
runs tests in devcontainers). ${{ github.action_path }} points at the runner
host, which is not mounted in containers, so the previously-merged
flaky-record-results would fail to find the bundled flaky_db.py there. And
the fetch/filter half of the pipeline had no shared equivalent, so a repo
couldn't remove its local flaky_db.py.

Changes

• flaky-filter (new composite action): fetch active marks for the branch
  and filter them out of a caller-provided test list → filtered TESTFILE.
  The caller still enumerates its own tests (LIST=1 make pytest etc. — that's
  product-specific); this action does only the generic fetch + filter.
  Fail-open: empty output ⇒ run the full suite.
• flaky-record-results (fixed): fetch the DB CLI into the mounted
  workspace via actions/checkout instead of github.action_path, so it works
  in container jobs. New ci-common-ref input (set it to your pinned ref).
• stale (re-added): opt-in reusable workflow (actions/stale) so
  issue-tracking repos (e.g. the public repo) can adopt it too.

Result

flaky-mark / flaky-unmark / flaky-filter / flaky-record-results now cover
the whole flaky pipeline and are container-safe — a consumer keeps only its
product-specific test enumeration and needs no local flaky_db.py. This
unblocks the flaky portion of the OSS adoption (RediSearch/RediSearch#10245).

Validated: strict-YAML (incl. dup-key) + compileall + actionlint via the repo's
own CI.

🤖 Generated with Claude Code

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Note

Medium Risk
Changes how CI talks to the flaky Redis DB and alters composite-action behavior in container test jobs; fail-open paths limit blast radius but misconfiguration could skip quarantine or record incorrectly.

Overview
Makes the shared flaky-test pipeline usable from container jobs and lets consumers drop a local flaky_db.py, plus adds an opt-in stale reusable workflow.

flaky-filter (new composite action) fetches branch-keyed marks from Redis and filters a caller-supplied test-id list into a TESTFILE. It fails open (empty testfile ⇒ run the full suite) and sets all-quarantined when every enumerated test was quarantined so shards can be skipped. flaky-record-results no longer invokes flaky_db.py via github.action_path; both actions checkout redisearch-ci-common into the mounted workspace and run the CLI from .redisearch-ci-common, with a new ci-common-ref input (default v1).

stale.yml is a reusable workflow_call wrapper around actions/stale@v10 with tunable stale/close days and runner label. README documents flaky-filter, container-safe usage, and the end-to-end flaky pipeline without per-repo CLI copies.

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[jit-ci]

🛡️ Jit Security Scan Results

✅ No security findings were detected in this PR

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[cursor]

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