Bumped checkout action

Author: tonsky

.github/workflows/build_test.yml

@@ -14,7 +14,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Choose Java 11
         run: |
           echo "JAVA_HOME=$JAVA_HOME_11_X64" >> $GITHUB_ENV