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/ci_decrypt-oracle.yaml

@@ -7,7 +7,7 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v4
         with:
           # The oracle will run on a Python 3.9 Lamba
@@ -34,7 +34,7 @@ jobs:
           - flake8-tests
           - pylint-tests
     steps:
-        - uses: actions/checkout@v4
+        - uses: actions/checkout@v6
         - uses: actions/setup-python@v4
           with:
             python-version: 3.9

.github/workflows/ci_static-analysis.yaml

@@ -23,7 +23,7 @@ jobs:
           - black-check
           - isort-check
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v4
         with:
           python-version: 3.8

.github/workflows/ci_test-vector-handler.yaml

@@ -44,7 +44,7 @@ jobs:
           aws-access-key-id: ${{ secrets.INTEG_AWS_ACCESS_KEY_ID }}
           aws-secret-access-key: ${{ secrets.INTEG_AWS_SECRET_ACCESS_KEY }}
           aws-region: us-west-2
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python }}
@@ -71,7 +71,7 @@ jobs:
           - flake8-tests
           - pylint-tests
     steps:
-        - uses: actions/checkout@v4
+        - uses: actions/checkout@v6
         - uses: actions/setup-python@v4
           with:
             python-version: 3.9

.github/workflows/ci_tests.yaml

@@ -70,7 +70,7 @@ jobs:
         run: |
           git config --global core.longpaths true
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python }}
@@ -91,7 +91,7 @@ jobs:
           - nocmk
           - test-upstream-requirements-py311
     steps:
-        - uses: actions/checkout@v4
+        - uses: actions/checkout@v6
         - uses: actions/setup-python@v4
           with:
             python-version: "3.11"

.github/workflows/repo-sync.yml

@@ -9,7 +9,7 @@ jobs:
     environment: repo-sync
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: repo-sync/github-sync@v2
       name: Sync repo to branch
       with: