* Migrate existing `open_registrations` setting to the new `registrations_mode`

Fixes #10263

* Remove unrelated db changes that have creeped in

Fix #6856
Fix #6951

Bumps [rails](https://github.com/rails/rails) from 5.2.2 to 5.2.2.1. **This update includes security fixes.**
- [Release notes](https://github.com/rails/rails/releases)
- [Commits](https://github.com/rails/rails/compare/v5.2.2...v5.2.2.1

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Add UI for enabling/disabling poll notifications

* Add poll notifications to the (advanced) quick filter bar

* Update poll notification message

“Your poll has ended” → “A poll you have voted in has ended”

* Clear up associated notifications when a poll is deleted

* yarn manage:translations && i18n-tasks add-missing

* Update Japanese translations for new landing page.

I don't change the tagline from English yet.
I think that translating a tagline is difficult and requires time-consuming discussions.

Some translations related about the poll are already done in Weblate, so I will leave it as it is.

Bumps [active_record_query_trace](https://github.com/brunofacca/active-record-query-trace) from 1.6.1 to 1.6.2.
- [Release notes](https://github.com/brunofacca/active-record-query-trace/releases)
- [Changelog](https://github.com/brunofacca/active-record-query-trace/blob/master/HISTORY.md)
- [Commits](https://github.com/brunofacca/active-record-query-trace/compare/v1.6.1...v1.6.2

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Fix poll update handler calling method was that was not available

Fix regression from #10209

* Refactor VoteService

* Refactor ActivityPub::DistributePollUpdateWorker and optimize it

* Fix typo

* Fix typo

Bumps [concurrent-ruby](https://github.com/ruby-concurrency/concurrent-ruby) from 1.1.4 to 1.1.5.
- [Release notes](https://github.com/ruby-concurrency/concurrent-ruby/releases)
- [Changelog](https://github.com/ruby-concurrency/concurrent-ruby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ruby-concurrency/concurrent-ruby/compare/v1.1.4...v1.1.5

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Squish username before validation (#10101)

Fix #10101

* Move before_validation hook to a private method

Also add Unicode wite-spaces to the spec to support the use of squish
over strip.

Fix #10116

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.30.1 to 1.31.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/1.30.1...1.31.0

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Query by @tateisu

Fix #1554

Bumps [pkg-config](https://github.com/ruby-gnome2/pkg-config) from 1.3.5 to 1.3.6.
- [Release notes](https://github.com/ruby-gnome2/pkg-config/releases)
- [Changelog](https://github.com/ruby-gnome2/pkg-config/blob/master/NEWS)
- [Commits](https://github.com/ruby-gnome2/pkg-config/compare/1.3.5...1.3.6

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [active_record_query_trace](https://github.com/brunofacca/active-record-query-trace) from 1.6 to 1.6.1.
- [Release notes](https://github.com/brunofacca/active-record-query-trace/releases)
- [Changelog](https://github.com/brunofacca/active-record-query-trace/blob/master/HISTORY.md)
- [Commits](https://github.com/brunofacca/active-record-query-trace/compare/v1.6...v1.6.1

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Fix #10223

Under load, multiple backups for a single user could be planned, which
is very expensive.

* Process incoming poll tallies update

* Send Update on poll vote

* Do not send Updates for a poll more often than once every 3 minutes

* Include voters in people to notify of results update

* Schedule closing poll worker on poll creation

* Add new notification type for ending polls

* Add front-end support for ended poll notifications

* Fix UpdatePollSerializer

* Fix Updates not being triggered by local votes

* Fix tests failure

* Fix web push notifications for closing polls

* Minor cleanup

* Notify voters of both remote and local polls when those close

* Fix delivery of poll updates to mentioned accounts and voters

* Reject existing Follows when suspending a remote account

Partial fix to #10229

* Add tests

* Fix SSL configuration regression in streaming API

Fix #10223

* Fix code style issues and integrate #10219

* Fix dumb thing

Fix #10177 for real

- Always run apt update before any other apt command. (This fixes
  incremental builds failing if a remote package is updated.)
- Only copy dependency lists before installing dependencies. (This means
  editing code doesn't force all dependencies to be re-downloaded.)
- Delete cache in the same layer that it is created. (Otherwise,
  deleting cache *increases* the size of the image on non-squashed
  builds.)
- Move the installation of some static dependencies to *before* Mastodon
  code is imported to Docker.

* config: add DB_SSLMODE for managed/remote PG

* streaming: set PG sslmode, defaults to prefer

Bumps [pkg-config](https://github.com/ruby-gnome2/pkg-config) from 1.3.4 to 1.3.5.
- [Release notes](https://github.com/ruby-gnome2/pkg-config/releases)
- [Changelog](https://github.com/ruby-gnome2/pkg-config/blob/master/NEWS)
- [Commits](https://github.com/ruby-gnome2/pkg-config/compare/1.3.4...1.3.5

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Do not allow adding votes to expired polls

* Only validate expires_at on create

* Immediately display poll results to poll author

* Refactor Poll#loaded_options and add Poll#voted? to improve DRYness