docs: align README example with actions/checkout@v7

Keep the usage snippet consistent with the lint workflow after the
Dependabot bump.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: setoelkahfi

README.md

@@ -20,7 +20,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
       - uses: smbcloudXYZ/smbcloud-deploy-action@v1
         with:
           token: ${{ secrets.SMB_TOKEN }}