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

Conflicts:
- `app/controllers/accounts_controller.rb`:
  Upstream introduced support for private pinned toots, but glitch-soc's query
  was a bit different as it filtered out local-only toots.
  Used upstream's query, while adding local-only filtering back.
- `app/controllers/activitypub/collections_controller.rb`:
  Same thing with regards to local-only posts.
- `app/validators/status_pin_validator.rb`:
  Not a real conflict, but the line below was different in glitch-soc due to
  the configurable pinned toots limit.

app/javascript/mastodon/features/status/components/action_bar.js

@@ -188,6 +188,7 @@ class ActionBar extends React.PureComponent {
     const { status, relationship, intl } = this.props;
 
     const publicStatus       = ['public', 'unlisted'].includes(status.get('visibility'));
+    const pinnableStatus     = ['public', 'unlisted', 'private'].includes(status.get('visibility'));
     const mutingConversation = status.get('muted');
     const account            = status.get('account');
     const writtenByMe        = status.getIn(['account', 'id']) === me;
@@ -201,7 +202,7 @@ class ActionBar extends React.PureComponent {
     }
 
     if (writtenByMe) {
-      if (publicStatus) {
+      if (pinnableStatus) {
         menu.push({ text: intl.formatMessage(status.get('pinned') ? messages.unpin : messages.pin), action: this.handlePinClick });
         menu.push(null);
       }