ci: remove dead Homebrew formula bump workflow

This workflow has been failing for years due to an expired/missing
COMMITTER_TOKEN. Homebrew maintains their own automated version
bump pipeline, making this redundant.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/homebrew.yml

@@ -1,19 +0,0 @@
----
-name: homebrew
-
-on:
-  push:
-    tags: '*'
-
-jobs:
-  homebrew:
-    name: Bump Homebrew formula
-    runs-on: ubuntu-latest
-    steps:
-      - uses: mislav/bump-homebrew-formula-action@v1
-        with:
-          # A PR will be sent to github.com/Homebrew/homebrew-core to update
-          # this formula:
-          formula-name: cheat
-        env:
-          COMMITTER_TOKEN: ${{ secrets.COMMITTER_TOKEN }}