[CI] Format develop (#11893)

.github/workflows/format.yaml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
     - master
+    - develop
 
 jobs:
   format:
@@ -14,6 +15,8 @@ jobs:
     if: github.repository == 'qmk/qmk_firmware'
 
     steps:
+    - uses: rlespinasse/github-slug-action@v3.x
+
     - uses: actions/checkout@v2
       with:
         token: ${{ secrets.API_TOKEN_GITHUB }}
@@ -37,6 +40,7 @@ jobs:
       uses: peter-evans/create-pull-request@v3
       with:
         delete-branch: true
+        branch: bugfix/format_${{ env.GITHUB_REF_SLUG }}
         author: QMK Bot <hello@qmk.fm>
         committer: QMK Bot <hello@qmk.fm>
         commit-message: Format code according to conventions