Add more JVM repositories

Added `apache/pekko` and `arrow-kt/arrow`.

Author: jupblb

.github/workflows/scip-examples.yaml

@@ -22,6 +22,10 @@ jobs:
             scip_binary: scip-go
           - repository: google/guava
             scip_binary: scip-java
+          - repository: arrow-kt/arrow
+            scip_binary: scip-java
+          - repository: apache/pekko
+            scip_binary: scip-java
 
     container: sourcegraph/${{ matrix.target.scip_binary }}:latest
     concurrency:
@@ -32,7 +36,6 @@ jobs:
         uses: actions/checkout@v5
         with:
           repository: ${{ matrix.target.repository }}
-          ref: master
           fetch-depth: 1
 
       - name: Cache Maven dependencies