Bump Homebrew/actions/setup-homebrew from 2026.09.13.1 to 2026.09.21.1

Bumps [Homebrew/actions/setup-homebrew](https://github.com/homebrew/actions) from 2026.09.13.1 to 2026.09.21.1.
- [Release notes](https://github.com/homebrew/actions/releases)
- [Changelog](https://github.com/Homebrew/actions/blob/main/release.test.mts)
- [Commits](https://github.com/homebrew/actions/compare/1e34f2e2acaa766b7efacb8c26352e6abbb023f9...848c272c7bfe984a197bd4d16383f4c106ec61e6)

---
updated-dependencies:
- dependency-name: Homebrew/actions/setup-homebrew
  dependency-version: 2026.09.21.1
  dependency-type: direct:production
...

See gh-51846

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/verify.yml

@@ -55,7 +55,7 @@ jobs:
           java-version: 17
       - name: Set Up Homebrew
         if: ${{ !vars.COMMERCIAL }}
-        uses: Homebrew/actions/setup-homebrew@1e34f2e2acaa766b7efacb8c26352e6abbb023f9 # 2026.09.13.1
+        uses: Homebrew/actions/setup-homebrew@848c272c7bfe984a197bd4d16383f4c106ec61e6 # 2026.09.21.1
         with:
           stable: true
       - name: Set Up Gradle