* Remove obsolete RSS::Serializer test

Since #17828, RSS::Serializer no longer has specific code for deleted statuses,
but it is never called on deleted statuses anyway.

* Rename erroneously-named test files

* Fix failing test

* Fix test deprecation warnings

* Update CircleCI Ruby orb

1.4.0 has a bug that does not match all the test files due to incorrect
globbing

Found via `codespell -q 3 -S ./CHANGELOG.md,./AUTHORS.md,./config/locales,./app/javascript/mastodon/locales -L ba,keypair,medias,ro`

* Add account_notes relationship

* Add tests

* Fix owned account notes not being deleted when an account is deleted

* Add post-migration to clean up orphaned account notes

* Fix deleting polls not deleting notifications

* Fix fav notification deletion when deleting a toot

* Refactor DeleteAccountService spec

* Add DeleteAccountService tests for other associations and notifications

* Add favourite handling spec in status removal

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

* Reject existing Follows when suspending a remote account

Partial fix to #10229

* Add tests

Fix #7316

* No need to re-require sidekiq plugins, they are required via Gemfile

* Add derailed_benchmarks tool, no need to require TTY gems in Gemfile

* Replace ruby-oembed with FetchOEmbedService

Reduce startup by 45382 allocated objects

* Remove preloaded JSON-LD in favour of caching HTTP responses

Reduce boot RAM by about 6 MiB

* Fix tests

* Fix test suite by stubbing out JSON-LD contexts