Fix legacy modules `check_username_for_spam` #4616

Job	Run time
check-lockfile	8s
lint-crlf	3s
lint-newsfile	37s
changes	2s
check-schema-delta	55s
lint	18s
check-sampleconfig	37s
Typechecking	1m 56s
lint-pydantic	48s
lint-clippy-nightly	0s
lint-clippy	0s
lint-readme	0s
lint-rustfmt	0s
linting-done	1s
calculate-test-jobs	8s
trial-olddeps	6m 57s
portdb (3.9, 13)	4m 37s
complement (monolith, SQLite)	13m 47s
portdb (3.13, 17)	3m 26s
complement (monolith, Postgres)	15m 3s
cargo-bench	0s
complement (workers, Postgres)	22m 40s
cargo-test	0s
trial-pypy	0s
trial (3.9, sqlite, all)	7m 31s
sytest (bullseye)	8m 58s
trial (3.9, postgres, 13, all)	13m 52s
sytest (bullseye, postgres)	10m 38s
trial (3.9, sqlite)	6m 2s
sytest (bullseye, multi-postgres, workers)	13m 41s
sytest (bullseye, multi-postgres, workers, asyncio)	18m 24s
export-data	3m 51s
tests-done	4s
	2h 35m 4s

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