Bump actions/checkout from 6.0.2 to 6.0.3

Bumps [actions/checkout](https://github.com/actions/checkout) from 6.0.2 to 6.0.3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Commits](actions/checkout@v6.0.2...v6.0.3)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
         - { os: windows-latest, ruby: head }
 
     steps:
-      - uses: actions/checkout@v6.0.2
+      - uses: actions/checkout@v6.0.3
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1

.github/workflows/push_gem.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           egress-policy: audit
 
-      - uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 # v5.0.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v5.0.1
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@d5126b9b3579e429dd52e51e68624dda2e05be25 # v1.267.0

.github/workflows/sync-ruby.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository_owner == 'ruby' }}
     steps:
-      - uses: actions/checkout@v6.0.2
+      - uses: actions/checkout@v6.0.3
 
       - name: Create GitHub App token
         id: app-token