Bump actions/setup-python from 2 to 4 (#690)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2 to 4.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
 
     steps:
       - uses: "actions/checkout@v3"
-      - uses: "actions/setup-python@v2"
+      - uses: "actions/setup-python@v4"
         with:
           python-version: ${{ matrix.python-version }}
       - name: "Install dependencies"
@@ -52,7 +52,7 @@ jobs:
       TOXENV: ${{ matrix.toxenv }}
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
         with:
           python-version: 3.8
       - name: "Install dependencies"