refactor(core): MaybeSend does not need to be unsafe (#5338) #2059

Job	Run time
build_all_features	5m 15s
build_all_platforms (ubuntu-latest)	2m 42s
build_default_features (ubuntu-latest)	37s
build_all_platforms (macos-latest)	2m 59s
build_under_wasm	50s
build_default_features (macos-latest)	39s
build_all_platforms (windows-latest)	6m 25s
build_default_features (windows-latest)	1m 54s
check_clippy	4m 2s
check_docs	4m 15s
check_msrv	39s
unit	7m 6s
	37m 23s

Provide feedback