Disable cacheHitSempahore if async execution is enabled.

`cacheHitSemaphore` is used to throttle the number of concurrent cache checks to the number of CPU. With async execution, the size of underlying thread pool is already limited to the number of CPU making the semaphore unnecessary.

PiperOrigin-RevId: 627036668
Change-Id: I2f664ddd7c35b8081f7432147c88bbaee063a8ba

src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java

@@ -306,12 +306,13 @@ void prepareForExecution(
     freeDiscoveredInputsAfterExecution =
         !trackIncrementalState && options.getOptions(CoreOptions.class).actionListeners.isEmpty();
 
+    this.useAsyncExecution = buildRequestOptions.useAsyncExecution;
+
     this.cacheHitSemaphore =
-        options.getOptions(CoreOptions.class).throttleActionCacheCheck
+        (!this.useAsyncExecution && options.getOptions(CoreOptions.class).throttleActionCacheCheck)
             ? new Semaphore(ResourceUsage.getAvailableProcessors())
             : null;
 
-    this.useAsyncExecution = buildRequestOptions.useAsyncExecution;
     // Always use semaphore for jobs if async execution is enabled.
     this.actionExecutionSemaphore =
         (this.useAsyncExecution || buildRequestOptions.useSemaphoreForJobs)