Tests

Remove `SYNAPSE_USE_FROZEN_DICTS` environment variable #4561

Job	Run time
changes	3s
lint-crlf	3s
check-lockfile	4s
lint-newsfile	35s
lint	18s
Typechecking	1m 34s
check-schema-delta	47s
check-sampleconfig	43s
lint-pydantic	1m 0s
lint-clippy	0s
lint-clippy-nightly	0s
lint-readme	0s
lint-rustfmt	0s
linting-done	2s
calculate-test-jobs	5s
trial-olddeps	6m 59s
portdb (3.9, 13)	3m 27s
complement (monolith, SQLite)	13m 29s
trial-pypy	0s
portdb (3.13, 17)	3m 26s
complement (monolith, Postgres)	14m 40s
complement (workers, Postgres)	22m 4s
cargo-bench	0s
cargo-test	0s
sytest (bullseye)	8m 27s
trial (3.9, sqlite, all)	5m 59s
sytest (bullseye, postgres)	10m 30s
trial (3.9, postgres, 13, all)	13m 28s
sytest (bullseye, multi-postgres, workers)	13m 30s
trial (3.9, sqlite)	5m 45s
sytest (bullseye, multi-postgres, workers, asyncio)	19m 29s
export-data	2m 16s
tests-done	2s
	2h 28m 45s

Provide feedback