chore(deps): update actions/checkout action to v6 (#53)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
   ci:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - run: corepack enable
       - uses: actions/setup-node@v6
         with:

.github/workflows/provenance.yml

@@ -13,7 +13,7 @@ jobs:
   check-provenance:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Check provenance downgrades