chore: remove graalvm kokoro github status (#713)

* chore: remove graalvm kokoro github status and unused cfgs

Author: mpeddada1

.github/sync-repo-settings.yaml

@@ -34,8 +34,6 @@ branchProtectionRules:
     - "units (8)"
     - "units (11)"
     - "Kokoro - Test: Integration"
-    - "Kokoro - Test: Java GraalVM Native Image"
-    - "Kokoro - Test: Java 17 GraalVM Native Image"
     - "Kokoro - Test: Docker Image Validation"
     - "dependencies (11, java-bigquery)"
     - "dependencies (11, java-spanner)"