Revert WorkflowSignalOperation (#1801) #2577

Job	Run time
build-and-test (ubuntu-latest, oldstable)	16m 49s
cloud-test (oldstable)	19s
build-and-test (ubuntu-latest, stable)	24m 38s
cloud-test (stable)	32s
build-and-test (macos-intel, oldstable)	19m 15s
build-and-test (macos-intel, stable)	17m 29s
build-and-test (macos-arm, oldstable)	16m 41s
build-and-test (macos-arm, stable)	18m 37s
build-and-test (windows-latest, oldstable)	21m 13s
build-and-test (windows-latest, stable)	21m 53s
features-test / test	2m 0s
	2h 39m 26s

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