Improve perf of sync device lists #1213

Job	Run time
changes	4s
lint-crlf	5s
check-lockfile	4s
lint-newsfile	31s
lint	46s
lint-clippy	0s
Typechecking	1m 42s
lint-pydantic	41s
lint-clippy-nightly	0s
lint-rustfmt	0s
check-sampleconfig	38s
check-schema-delta	41s
linting-done	3s
calculate-test-jobs	6s
trial-olddeps	6m 47s
complement (monolith, SQLite)	12m 54s
portdb (3.8, 11)	2m 59s
complement (monolith, Postgres)	13m 29s
trial-pypy	0s
complement (workers, Postgres)	20m 30s
cargo-bench	0s
portdb (3.11, 15)	2m 54s
cargo-test	0s
trial (3.8, sqlite, all)	4m 16s
sytest (focal)	8m 16s
trial (3.8, postgres, 11, all)	10m 12s
sytest (focal, postgres)	10m 0s
trial (3.8, sqlite)	3m 47s
sytest (focal, multi-postgres, workers)	13m 54s
sytest (focal, multi-postgres, workers, asyncio)	19m 50s
export-data	2m 10s
tests-done	2s
	2h 17m 21s

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