increase degree of concurreny to max 25 (20 for e2e and 5 for e2e-graal).

Author: phipag

.github/workflows/check-e2e.yml

@@ -93,7 +93,7 @@ jobs:
     environment: E2E
     strategy:
       fail-fast: false
-      max-parallel: 10
+      max-parallel: 20
       matrix:
         java:
           - 11