Bump actions/checkout to v7.0.0

Pin to 9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 (v7.0.0).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: patocallaghan

.github/workflows/publish.yml

@@ -15,7 +15,7 @@ jobs:
   verify:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd   # v6.0.2
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0   # v7.0.0
         with:
           persist-credentials: false
           fetch-depth: 0                   # full history for the ancestry check below
@@ -45,7 +45,7 @@ jobs:
       contents: read
       id-token: write           # OIDC trusted publishing: only this job mints the token
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd   # v6.0.2
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0   # v7.0.0
         with: { persist-credentials: false }
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with: