Update actions/checkout action to v4 (#54)

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

Author: renovate[bot]

.github/workflows/PR.yml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout the repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup JDK
         uses: actions/setup-java@v3

.github/workflows/master.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 

.github/workflows/release.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout the repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
           ref: ${{ github.event.inputs.branch }}