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

Conflicts:
- `app/controllers/activitypub/collections_controller.rb`:
  Conflict due to glitch-soc having to take care of local-only
  pinned toots in that controller.
  Took upstream's changes and restored the local-only special
  handling.
- `app/controllers/auth/sessions_controller.rb`:
  Minor conflicts due to the theming system, applied upstream
  changes, adapted the following two files for glitch-soc's
  theming system:
  - `app/controllers/concerns/sign_in_token_authentication_concern.rb`
  - `app/controllers/concerns/two_factor_authentication_concern.rb`
- `app/services/backup_service.rb`:
  Minor conflict due to glitch-soc having to handle local-only
  toots specially. Applied upstream changes and restored
  the local-only special handling.
- `app/views/admin/custom_emojis/index.html.haml`:
  Minor conflict due to the theming system.
- `package.json`:
  Upstream dependency updated, too close to a glitch-soc-only
  dependency in the file.
- `yarn.lock`:
  Upstream dependency updated, too close to a glitch-soc-only
  dependency in the file.

.github/dependabot.yml

@@ -0,0 +1,22 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: "/"
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 99
+    allow:
+      - dependency-type: all
+
+  - package-ecosystem: bundler
+    directory: "/"
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 99
+    allow:
+      - dependency-type: all