Bump actions/checkout from 3 to 4 (#29)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
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-manifest.yml

@@ -18,7 +18,7 @@ jobs:
         shell: bash -l {0}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 

.github/workflows/ci-release.yml

@@ -24,7 +24,7 @@ jobs:
       WF_VERSION_FNAME: "version.txt"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 

.github/workflows/refresh-lockfiles.yml

@@ -24,7 +24,7 @@ jobs:
     outputs:
       matrix: ${{ steps.get_py.outputs.matrix }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - id: get_py
         run: echo "MATRIX=$(ls -1 requirements/py*.yml | xargs -n1 basename | sed 's/....$//' | jq -cnR '[inputs]')" >> ${GITHUB_OUTPUT}
 
@@ -40,7 +40,7 @@ jobs:
         python: ${{ fromJSON(needs.get_python_matrix.outputs.MATRIX) }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: install requirements
         run: |
           source $CONDA/bin/activate base
@@ -65,7 +65,7 @@ jobs:
     needs: gen_lockfiles
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: get artifacts
         uses: actions/download-artifact@v3
         with: