This PR:
* Reduces the amount of noise in the `check-newsfragment` CI output by hiding the dependency installation output by default.
* Prints a link to the changelog/debian changelog section of the contributing guide if an error is found.
* 'release-v1.15.0' of github.com:matrix-org/synapse: (55 commits)
1.15.0
Fix some attributions
Update CHANGES.md
1.15.0rc1
Revert "1.15.0rc1"
1.15.0rc1
Fix bug in account data replication stream. (#7656)
Convert the registration handler to async/await. (#7649)
Accept device information at the login fallback endpoint. (#7629)
Convert user directory handler and related classes to async/await. (#7640)
Add an option to disable autojoin for guest accounts (#6637)
Clarifications to the admin api documentation (#7647)
Update to the stable SSO prefix for UI Auth. (#7630)
Fix type information on `assert_*_is_admin` methods (#7645)
Remove some unused constants. (#7644)
Typo fixes.
Allow new users to be registered via the admin API even if the monthly active user limit has been reached (#7263)
Add device management to admin API (#7481)
Attempt to fix PhoneHomeStatsTestCase.test_performance_100 being flaky. (#7634)
Support CS API v0.6.0 (#6585)
...
* You need an entry in the debian changelog (and not a regular newsfragment)
for debian packaging changes.
* Regular newsfragments must end in full stops.
