chore(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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] <support@github.com>

Author: dependabot[bot]

.github/workflows/integration.yml

@@ -19,28 +19,28 @@ jobs:
 
     steps:
       - name: Checkout main repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Checkout relay
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: agentanycast/agentanycast-relay
           path: agentanycast-relay
 
       - name: Checkout node
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: agentanycast/agentanycast-node
           path: agentanycast-node
 
       - name: Checkout proto
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: agentanycast/agentanycast-proto
           path: agentanycast-proto
 
       - name: Checkout python SDK
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: agentanycast/agentanycast-python
           path: agentanycast-python