Serialization Refactor #18543

Job	Run time
doctest (1.10, Linux, RPTU, normal-memory)	22m 55s
extra-long-test	0s
doctest (1.11, Linux, RPTU, normal-memory)	19m 55s
test (1.6, short, Linux)	6m 23s
test (1.6, long, Linux)	18m 3s
doctest (nightly, Linux, RPTU, normal-memory)	26m 54s
test (1.10, short, Linux)	8m 57s
doctest (1.10, Linux, RPTU, normal-memory, depwarn=error)	22m 56s
test (1.10, long, Linux)	17m 29s
doctest (1.10, macOS, RPTU)	12m 27s
test (1.11, short, Linux)	4m 14s
test (1.11, long, Linux)	6m 45s
test (nightly, short, Linux)	5m 0s
test (nightly, long, Linux)	16m 23s
test (1.10, short, Linux, RPTU, high-memory, depwarn=error)	9m 31s
test (1.10, long, Linux, RPTU, normal-memory, depwarn=error)	17m 28s
test (1.10, short, macOS, RPTU)	4m 3s
test (1.10, long, macOS, RPTU)	11m 23s
test (1.10, book, Linux, RPTU, normal-memory)	37m 17s
test (nightly, book, Linux, RPTU, normal-memory)	2h 30m 15s
	6h 58m 18s

Provide feedback