chore(ci): replace bump-homebrew-formula-action with manual PR step

mislav/bump-homebrew-formula-action@v4.1 fatals on the GitHub tarball
HEAD's HTTP 303 redirect (upstream issue #340, open since 2026-05-16).
Every release since blocked the Homebrew/homebrew-core PR step, so the
official formula had to be bumped by hand after each tag.

Inline the shell equivalent: sync the tw93/homebrew-core fork to
upstream main, rewrite Formula/m/mole.rb with the new url + source
sha256 and drop the bottle block (Homebrew CI rebuilds), push the
mole-<version> branch and open the PR via gh. Idempotent on re-run:
push uses --force-with-lease and gh pr create is skipped when a PR
for the branch already exists. continue-on-error stays on so a
Homebrew core hiccup never blocks the rest of the release flow.