Fix CI: replace Java 13 with 17, unique artifact names

Temurin does not distribute Java 13 (non-LTS, EOL). Replace with
Java 17 (current LTS). Also make upload-artifact names unique per
matrix job as required by actions/upload-artifact@v4.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Greyvend

.github/workflows/build_and_test.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       matrix:
         # test against latest update of each major Java version, as well as specific updates of LTS versions:
-        java: [8, 11.0.x, 13 ]
+        java: [8, 11, 17 ]
 
     steps:
     - name: Checkout the code
@@ -56,7 +56,7 @@ jobs:
     - name: Upload build artifacts
       uses: actions/upload-artifact@v4
       with:
-        name: Package
+        name: Package-java-${{ matrix.java }}
         path: staging
 
     - name: Notify slack fail