changelog.d/12333.bugfix

-Fix a long-standing bug affecting URL previews that would generate a 500 response instead of a 403 if the previewed URL includes a port that isn't allowed by the relevant blacklist.

changelog.d/12334.misc

-Remove the `tox` packaging job: it will be redundant once #11537 lands.

changelog.d/12335.misc

-Ignore `.envrc` for `direnv` users.

changelog.d/12336.misc

-Remove the (broadly unused, dev-only) dockerfile for pg tests.

changelog.d/12338.misc

-Refactor relations code to remove an unnecessary class.

changelog.d/12339.doc

-Upgrade the version of `mdbook` in CI to 0.4.17.

changelog.d/12341.feature

-Allow setting user admin status using the module API. Contributed by Famedly.

changelog.d/12346.misc

-Remove redundant `get_success` calls in test code.

changelog.d/12347.misc

-Add type annotations for `tests/unittest.py`.

changelog.d/12348.misc

-Move single-use methods out of `TestCase`.

changelog.d/12349.misc

-Remove broken and unused development scripts.

changelog.d/12350.bugfix

-Default to `private` room visibility rather than `public` when a client does not specify one, according to spec.
\ No newline at end of file

changelog.d/12351.misc

-Remove broken and unused development scripts.
\ No newline at end of file

changelog.d/12353.misc

-Convert `Linearizer` tests from `inlineCallbacks` to async.

changelog.d/12354.misc

-Update docstrings for `ReadWriteLock` tests.

changelog.d/12355.misc

-Remove broken and unused development scripts.
\ No newline at end of file

changelog.d/12357.misc

-Refactor `Linearizer`, convert methods to async and use an async context manager.

changelog.d/12358.misc

-Fix a long-standing bug where `Linearizer`s could get stuck if a cancellation were to happen at the wrong time.

changelog.d/12364.bugfix

-Fix a spec compliance issue where requests to the `/publicRooms` federation API would specify `limit` as a string.
\ No newline at end of file

changelog.d/12366.misc

-Make `StreamToken.from_string` and `RoomStreamToken.parse` propagate cancellations instead of replacing them with `SynapseError`s.