feat(lib): missing Timer will warn or panic #2296

Job	Run time
Check Style	5s
Verify hyper.h is up to date	48s
Test with Miri	50s
features	13s
Check MSRV	53s
Test C API (FFI)	29s
udeps	27s
Test stable on ubuntu-latest	2m 4s
Test stable on windows-latest	3m 12s
Test stable on macOS-latest	1m 37s
Test beta on ubuntu-latest	2m 22s
Test beta on windows-latest	2m 51s
Test beta on macOS-latest	2m 46s
Test nightly on ubuntu-latest	1m 17s
Test nightly on windows-latest	3m 7s
Test nightly on macOS-latest	2m 27s
Build docs	21s
Check exposed types	22s
CI is green	1s
	26m 12s

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