ci(deps): bump actions/checkout from 2 to 3

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>

.github/workflows/black.yml

@@ -12,7 +12,7 @@ jobs:
 
     name: Code Style
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: actions/setup-python@v3
       with:
         python-version: 3.9

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
         name: Build and release to PyPI
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v1
+            - uses: actions/checkout@v3
             - name: Set up Python
               uses: actions/setup-python@v3
               with:

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
 
     name: Doc tests (Python ${{ matrix.python_version }} on ${{ matrix.os }})
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python_version }}
       uses: actions/setup-python@v3
       with: