Add a way to unregister life-cycle listeners #5715

Job	Run time
build (stable, examples/counter)	1m 25s
build (stable, examples/marvel)	49s
build (stable, examples/pub)	47s
build (stable, examples/random_number)	48s
build (stable, examples/stackoverflow)	46s
build (stable, examples/todos)	1m 18s
build (stable, packages/riverpod)	2m 4s
build (stable, packages/riverpod/example)	54s
build (stable, packages/flutter_riverpod)	1m 33s
build (stable, packages/flutter_riverpod/example)	1m 16s
build (stable, packages/hooks_riverpod)	1m 22s
build (stable, packages/hooks_riverpod/example)	1m 15s
build (stable, packages/riverpod_annotation)	47s
build (stable, packages/riverpod_generator)	1m 47s
build (stable, packages/riverpod_generator/integration/build_yaml)	1m 16s
build (stable, website)	45s
build (master, examples/counter)	1m 44s
build (master, examples/marvel)	1m 7s
build (master, examples/pub)	1m 13s
build (master, examples/random_number)	1m 6s
build (master, examples/stackoverflow)	1m 11s
build (master, examples/todos)	1m 46s
build (master, packages/riverpod)	2m 36s
build (master, packages/riverpod/example)	51s
build (master, packages/flutter_riverpod)	2m 0s
build (master, packages/flutter_riverpod/example)	1m 39s
build (master, packages/hooks_riverpod)	1m 37s
build (master, packages/hooks_riverpod/example)	1m 32s
build (master, packages/riverpod_annotation)	57s
build (master, packages/riverpod_generator)	2m 9s
build (master, packages/riverpod_generator/integration/build_yaml)	1m 24s
build (master, website)	1m 10s
	42m 54s

Provide feedback