feat: `post_release()` no longer checks if on release branch

[krlmlr]

.

[aviator-app[bot]]

Current Aviator status

Aviator will automatically update this comment as the status of the PR changes. Comment /aviator refresh to force Aviator to re-examine your PR (or learn about other /aviator commands).

This PR was merged using Aviator.

---

See the real-time status of this PR on the Aviator webapp.

Use the Aviator Chrome Extension to see the status of your PR within GitHub.

[aviator-app[bot]]

This pull request failed to merge: some CI status(es) failed. Remove the blocked label to re-queue.

Failed CI(s): Smoke test: stock R