GHA: Upgrades actions/checkout to v4

.github/workflows/check.yml

@@ -10,8 +10,8 @@ jobs:
   Pre-commit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/cache@v3
+      - uses: actions/checkout@v4
+      - uses: actions/cache@v4
         with:
           path: ~/.cache/pre-commit
           key: pre-commit|${{ hashFiles('.pre-commit-config.yaml') }}

.github/workflows/docker.yml

@@ -27,15 +27,15 @@ jobs:
   Hadolint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: brpaz/hadolint-action@master
         with:
           dockerfile: Dockerfile
   Docker:
     runs-on: ubuntu-latest
     needs: Hadolint
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Build ubuntu-base
         run: docker build --target ubuntu-base -t ubuntu-base .
       - name: Build ubuntu-provisioned

.github/workflows/sync-fork.yml

@@ -14,11 +14,11 @@ jobs:
     if: github.repository != 'EA31337/EA-Tester'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
           persist-credentials: false
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
           path: upstream

.github/workflows/tests-mql.yml

@@ -37,7 +37,7 @@ jobs:
           - TestModellingQuality
           - TestTimeframes
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check dependencies
         if: github.actor == 'nektos/act'
         run: >
@@ -61,7 +61,7 @@ jobs:
           - TestLotstep5  # @fixme: GH-208
           - TestSpread    # @fixme: GH-209
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check dependencies
         if: github.actor == 'nektos/act'
         run: >