Async: Drop-in SyncCancelerForAsyncWork without execUncancelableSegment*

We're doing this to prep for the coro port

stimBuffApis/livoxGen1/ioUringAssemblyEngine.h

@@ -19,7 +19,7 @@
 #include <spinscale/cps/asynchronousContinuation.h>
 #include <spinscale/asynchronousLoop.h>
 #include <spinscale/cps/callback.h>
-#include <spinscale/spinLock.h>
+#include <spinscale/syncCancelerForAsyncWork.h>
 #include <user/frameAssemblyDesc.h>
 #include <user/stagingBuffer.h>
 
@@ -80,12 +80,7 @@ private:
 	boost::asio::deadline_timer stallTimer;
 	// Callback for CQE ntfns (called with user_data+result from each CQE)
 	resetAndAssembleFrameCbFn onCqeReadyCallback;
-	/**	EXPLANATION:
-	 * Flag to indicate whether engine should accept new requests.
-	 * Set by setup(), cleared by stop().
-	 */
-	sscl::SpinLock shouldAcceptRequestsLock;
-	bool shouldAcceptRequests;
+	sscl::SyncCancelerForAsyncWork ioUringAssemblyEngnCanceler;
 
 	size_t nDgramsPerStagingBufferFrame;