Update actions/checkout action to v4 (#13)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/auto-readme.yml

@@ -24,7 +24,7 @@ jobs:
   update:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Find default branch name
         id: defaultBranch

.github/workflows/test-workflow.yml

@@ -6,7 +6,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: ./
         with:

.github/workflows/validate-codeowners.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout source code at current commit"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - uses: mszostok/[email protected]
         if: github.event.pull_request.head.repo.full_name == github.repository
         name: "Full check of CODEOWNERS"

action.yml

@@ -12,7 +12,7 @@ inputs:
 runs:
   using: composite
   steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         fetch-depth: 0