sec1: bump `serdect` dependency to v0.3.0-rc.0 #2473

Job	Run time
build (1.65.0, thumbv7em-none-eabi)	47s
test (1.65.0)	51s
build (1.65.0, wasm32-unknown-unknown)	47s
test (stable)	13s
build (stable, thumbv7em-none-eabi)	14s
build (stable, wasm32-unknown-unknown)	16s
minimal-versions / minimal-versions	21s
	3m 29s

Provide feedback