ci: stash rendered formula before checkout in source-repo commit step

`git checkout main` aborted on the v0.2.0 release because the
freshly-rendered Formula/dsmview.rb differed from the committed
version. Save it to /tmp first, then force-checkout main, then
restore. Release tap-push step already succeeded, so brew install
worked — only the back-commit refresh was missed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/release.yml

@@ -155,11 +155,14 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
+          # Stash the newly rendered formula before switching branches —
+          # otherwise `git checkout main` aborts when the working-tree
+          # formula differs from main's committed version.
+          cp Formula/dsmview.rb /tmp/dsmview.rb
           git config user.email "github-actions[bot]@users.noreply.github.com"
           git config user.name  "github-actions[bot]"
           git fetch origin main
-          git checkout main
-          cp Formula/dsmview.rb /tmp/dsmview.rb
+          git checkout -f main
           git pull --rebase origin main || true
           cp /tmp/dsmview.rb Formula/dsmview.rb
           git add Formula/dsmview.rb