Remove unused features #5609

Job	Run time
Release builds and tests	12m 46s
Basic Checks	21m 17s
Additional Builds and Concurrency Tests	17m 38s
Slow tests	23m 40s
Measure coverage	27m 35s
miri	4m 31s
sanitize (address)	19m 40s
sanitize (address, multi-threading)	20m 58s
sanitize (leak)	9m 35s
sanitize (leak, multi-threading)	9m 46s
	2h 47m 26s

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