serdect: bump `toml` to v0.8 (#1244) #1470

Job	Run time
build (1.65.0, thumbv7em-none-eabi)	4m 34s
build (1.65.0, wasm32-unknown-unknown)	4m 40s
build (stable, thumbv7em-none-eabi)	18s
test (1.65.0)	4m 41s
build (stable, wasm32-unknown-unknown)	12s
test (stable)	11s
minimal-versions / minimal-versions	30s
	15m 6s

Provide feedback