Revert "der: add `Error::(set_)source`; remove `Clone` + `Copy` (#132… #653

Job	Run time
build (1.75.0, thumbv7em-none-eabi)	30s
minimal-versions	0s
build (1.75.0, wasm32-unknown-unknown)	48s
build (stable, thumbv7em-none-eabi)	31s
test (1.75.0)	34s
build (stable, wasm32-unknown-unknown)	48s
test (stable)	39s
	3m 50s

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