Chore:Resolved EnginerGetClientVersionV1 fails for local build (#7687)

Signed-off-by: Preeti <35308865+pr9t@users.noreply.github.com>
Co-authored-by: Sally MacFarlane <macfarla.github@gmail.com>

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineGetClientVersionV1.java

@@ -49,9 +49,11 @@ public class EngineGetClientVersionV1 extends ExecutionEngineJsonRpcMethod {
 
   @Override
   public JsonRpcResponse syncResponse(final JsonRpcRequestContext request) {
+    String safeCommit =
+        (commit != null && commit.length() >= 8) ? commit.substring(0, 8) : "unknown";
     return new JsonRpcSuccessResponse(
         request.getRequest().getId(),
         new EngineGetClientVersionResultV1(
-            ENGINE_CLIENT_CODE, ENGINE_CLIENT_NAME, clientVersion, commit.substring(0, 8)));
+            ENGINE_CLIENT_CODE, ENGINE_CLIENT_NAME, clientVersion, safeCommit));
   }
 }