Bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...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/ci.yaml

@@ -7,7 +7,7 @@ jobs:
   works-input:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - uses: ./
         with:
           token: ${{ secrets.SPINNAKER_TOKEN }}
@@ -17,7 +17,7 @@ jobs:
   works-input-with-extra-params:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - uses: ./
         with:
           token: ${{ secrets.SPINNAKER_TOKEN }}
@@ -32,7 +32,7 @@ jobs:
       SPINNAKER_WEBHOOK_HOST: ${{ secrets.SPINNAKER_HOST }}
       SPINNAKER_WEBHOOK_NAME: ${{ secrets.SPINNAKER_NAME }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - uses: ./
 
   works-env-with-extra-params:
@@ -43,7 +43,7 @@ jobs:
       SPINNAKER_WEBHOOK_NAME: ${{ secrets.SPINNAKER_NAME }}
       SPINNAKER_WEBHOOK_EXTRA_PARAMS: '{"hello":"adam"}'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - uses: ./
 
   fails-no-token:
@@ -52,7 +52,7 @@ jobs:
       SPINNAKER_HOST: ${{ secrets.SPINNAKER_HOST }}
       SPINNAKER_WEBHOOK_NAME: ${{ secrets.SPINNAKER_NAME }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - run: |
           set +e
           ./spinnaker-webhook.sh
@@ -64,7 +64,7 @@ jobs:
       SPINNAKER_WEBHOOK_TOKEN: ${{ secrets.SPINNAKER_TOKEN }}
       SPINNAKER_WEBHOOK_NAME: ${{ secrets.SPINNAKER_NAME }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - run: |
           set +e
           ./spinnaker-webhook.sh
@@ -76,7 +76,7 @@ jobs:
       SPINNAKER_WEBHOOK_TOKEN: ${{ secrets.SPINNAKER_TOKEN }}
       SPINNAKER_WEBHOOK_HOST: ${{ secrets.SPINNAKER_HOST }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - run: |
           set +e
           ./spinnaker-webhook.sh