Bump purcell/setup-emacs

Bumps [purcell/setup-emacs](https://github.com/purcell/setup-emacs) from 92ece5b58c04d4c154ca49b58413b5373bfa83d8 to 8b415d39876e1f55baeadbe408cc708e34ecb67a.
- [Release notes](https://github.com/purcell/setup-emacs/releases)
- [Commits](purcell/setup-emacs@92ece5b...8b415d3)

---
updated-dependencies:
- dependency-name: purcell/setup-emacs
  dependency-type: direct:production
...

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

.github/workflows/test.yml

@@ -21,7 +21,7 @@ jobs:
           - 29.4
     steps:
       - uses: actions/checkout@v4
-      - uses: purcell/setup-emacs@92ece5b58c04d4c154ca49b58413b5373bfa83d8
+      - uses: purcell/setup-emacs@8b415d39876e1f55baeadbe408cc708e34ecb67a
         with:
           version: ${{ matrix.emacs-version }}
       - uses: leotaku/elisp-check@6a1fc6b11ae66dda13859f8b3474a36dfe3ef225