use new checkout api

Author: Simply007

.github/workflows/gradle.yml

@@ -18,7 +18,7 @@ jobs:
       CI: true
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up JDK 1.8
         uses: actions/setup-java@v2
         with:

.github/workflows/publish.yml

@@ -6,7 +6,7 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Java
         uses: actions/setup-java@v2
         with: