Bump actions/checkout from 2 to 3 (aio-libs#688)

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](actions/checkout@v2...v3)

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

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

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

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
     timeout-minutes: 5
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: Setup Python 3.8
       uses: actions/setup-python@v3
       with:
@@ -84,7 +84,7 @@ jobs:
     timeout-minutes: 15
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: Setup Python ${{ matrix.pyver }}
       uses: actions/setup-python@v3
       with:
@@ -158,7 +158,7 @@ jobs:
     needs: pre-deploy
     steps:
     - name: Checkout
-      uses: actions/checkout@v2.3.4
+      uses: actions/checkout@v3
     - name: Setup Python
       uses: actions/setup-python@v3
     - name: Install cython
@@ -195,7 +195,7 @@ jobs:
           qemu: s390x
     steps:
     - name: Checkout
-      uses: actions/checkout@v2.3.4
+      uses: actions/checkout@v3
     - name: Set up QEMU
       if: ${{ matrix.qemu }}
       uses: docker/setup-qemu-action@v1
@@ -235,7 +235,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v2.3.4
+      uses: actions/checkout@v3
     - name: Login
       run: |
         echo "${{ secrets.GITHUB_TOKEN }}" | gh auth login --with-token