fix checkout to use current repo instead of hardcoded upstream

Author: yiyuan-he

.github/workflows/java-eks-otlp-ocb-test.yml

@@ -77,7 +77,7 @@ jobs:
 
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 #5.0.0
         with:
-          repository: 'aws-observability/aws-application-signals-test-framework'
+          # Use the current repository (allows testing from forks)
           ref: ${{ env.CALLER_WORKFLOW_NAME == 'main-build' && 'main' || github.ref }}
           fetch-depth: 0