Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `.env.production.sample`:
  Copied upstream changes.
- `app/controllers/settings/identity_proofs_controller.rb`:
  Minor conflict due to glitch-soc's extra “enable_keybase” setting.
  Upstream removed keybase support altogether, so did the same.
- `app/controllers/well_known/keybase_proof_config_controller.rb`:
  Minor conflict due to glitch-soc's extra “enable_keybase” setting.
  Upstream removed keybase support altogether, so did the same.
- `lib/mastodon/statuses_cli.rb`:
  Minor conflict due to an optimization that wasn't shared between
  the two versions. Copied upstream's version.

db/post_migrate/20211126000907_drop_account_identity_proofs.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class DropAccountIdentityProofs < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    drop_table :account_identity_proofs
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end