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/dev-image.yml

@@ -9,7 +9,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       -
         name: Set up Docker Buildx
         uses: crazy-max/ghaction-docker-buildx@v3

.github/workflows/docker-image.yml

@@ -9,7 +9,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       -
         name: Set up Docker Buildx
         uses: crazy-max/ghaction-docker-buildx@v3

.github/workflows/test-backend.yml

@@ -13,7 +13,7 @@ jobs:
       run:
         working-directory: ./backend
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:

.github/workflows/tests.yaml

@@ -8,7 +8,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       -
         name: Set up Docker Buildx
         uses: crazy-max/ghaction-docker-buildx@v3