Update various GH actions to fix CI warnings

Author: pimterry

.github/workflows/ci.yml

@@ -6,25 +6,27 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Set up JRE 8 as libs for R8
-        uses: actions/setup-java@v1
+        uses: actions/setup-java@v3
         with:
           java-version: 8
+          distribution: adopt-hotspot
 
       - name: Set up JDK 14 for build
-        uses: actions/setup-java@v1
+        uses: actions/setup-java@v3
         with:
           java-version: 14
+          distribution: adopt-hotspot
 
       - name: Build & test the agent standalone
         run: ./gradlew quickTest
 
       - name: Build & test the full distributable
         run: ./gradlew distTest
 
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v3
         with:
           name: distributables
           path: build/libs/*-dist.jar