chore(internal): update actions/checkout version

Author: stainless-app[bot]

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ${{ github.repository == 'stainless-sdks/openlayer-typescript' && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Node
         uses: actions/setup-node@v4
@@ -41,7 +41,7 @@ jobs:
       contents: read
       id-token: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Node
         uses: actions/setup-node@v4

.github/workflows/publish-npm.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Node
         uses: actions/setup-node@v3

.github/workflows/release-doctor.yml

@@ -12,7 +12,7 @@ jobs:
     if: github.repository == 'openlayer-ai/openlayer-ts' && (github.event_name == 'push' || github.event_name == 'workflow_dispatch' || startsWith(github.head_ref, 'release-please') || github.head_ref == 'next')
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Check release environment
         run: |