perfect-numbers: sync #3104

Job	Run time
markdown lint	11s
Check exercises on nightly (benchmark enabled)	13s
Clippy	17s
Run shellcheck on scripts	5s
Run repository tests	1m 0s
Check compilation (stable)	16s
Check compilation (beta)	15s
configlet lint	7s
Check Rust Formatting	22s
	2m 46s

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