CI GitHub Actions: No need to mark Java >= 15 as known issue anymore (#15750)

.github/workflows/uberjar.yml

@@ -81,7 +81,7 @@ jobs:
     strategy:
       matrix:
         edition: [ee, oss]
-        java-version: [8, 11, 13]
+        java-version: [8, 11, 16]
     steps:
     - name: Prepare JRE (Java Run-time Environment)
       uses: actions/setup-java@v1
@@ -104,32 +104,3 @@ jobs:
     - name: Check API health
       run: curl -s localhost:3000/api/health
 
-  known-issue-java15:
-    runs-on: ubuntu-20.04
-    needs: build
-    timeout-minutes: 10
-    strategy:
-      matrix:
-        edition: [ee, oss]
-    steps:
-    - name: Prepare JRE 15
-      uses: actions/setup-java@v1
-      with:
-        java-package: jre
-        java-version: 15
-    - run: java -version
-
-    - uses: actions/download-artifact@v2
-      name: Retrieve uberjar artifact
-      with:
-        name: metabase-${{ matrix.edition }}-uberjar
-
-    - name: Launch uberjar
-      run: |
-        java -jar ./target/uberjar/metabase.jar &
-        sleep 180
-      timeout-minutes: 5
-
-    - name: Check API health
-      run: curl -s localhost:3000/api/health
-      continue-on-error: true