chore(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Use Node ${{ matrix.node }}
         uses: actions/setup-node@v5

.github/workflows/size.yml

@@ -6,7 +6,7 @@ jobs:
     env:
       CI_JOB_NUMBER: 1
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: andresz1/size-limit-action@v1
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}