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/build.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - name: Build Genesis Core
         env:
           PUSH_CFG: ${{ secrets.PUSH_CFG }}

.github/workflows/docs.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - uses: actions/setup-python@v5
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           ref: gh-pages
       - name: Setup Pages

.github/workflows/tests.yml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         python-version: [ "3.12" ]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
@@ -60,7 +60,7 @@ jobs:
           # Maps tcp port 5432 on service container to the host
           - 5432:5432
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
@@ -86,7 +86,7 @@ jobs:
       matrix:
         python-version: ["3.12"]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with: