Remove Timer::FireNow.

PiperOrigin-RevId: 811123106

internal/platform/implementation/apple/timer.mm

@@ -106,32 +106,5 @@ bool Timer::Stop() {
   return true;
 }
 
-bool Timer::FireNow() {
-  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void) {
-    absl::AnyInvocable<void()> callback_to_run;
-    {
-      absl::MutexLock lock(&mutex_);
-
-      // Don't fire if there's no callback or if a callback is already in progress.
-      if (!callback_ || callback_running_) {
-        return;
-      }
-      callback_running_ = true;
-      callback_to_run = std::move(callback_);
-    }
-
-    // Execute callback outside of the lock.
-    callback_to_run();
-    {
-      absl::MutexLock lock(&mutex_);
-      callback_ = std::move(callback_to_run);
-      callback_running_ = false;
-      condvar_.Signal();  // Notify Stop() if it's waiting.
-    }
-  });
-
-  return true;
-}
-
 }  // namespace apple
 }  // namespace nearby