Bump actions/checkout from 2 to 3 (#640)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v3)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/deploy-docs.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Master
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Set up Python 3.7
         uses: actions/setup-python@v2
         with:

.github/workflows/python-publish.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python
       uses: actions/setup-python@v2.2.2
       with:

.github/workflows/test-package.yml

@@ -42,7 +42,7 @@ jobs:
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python
       uses: actions/setup-python@v1
       with: