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

- `.env.production.sample`:
  Our sample config file is very different from upstream since it is much more
  complete. Upstream added documentation for a few env variables.
  Copied the new variables/documentation from upstream.
- `app/lib/feed_manager.rb`:
  Upstream added a timeline type (hashtags), while glitch-soc already had an
  extra one (direct messages). Not really a conflict but textually close
  changes.
  Ported upstream's changes.
- `app/models/custom_emoji.rb`:
  Upstream upped the custom emoji size limit, while glitch-soc had configurable
  limits.
  Upped the default limits accordingly.
- `streaming/index.js`:
  Upstream reworked how hastags were normalized. Minor conflict due to
  glitch-soc's handling of instance-local posts.
  Ported upstream's changes.

Gemfile

@@ -10,7 +10,7 @@ gem 'puma', '~> 5.6'
 gem 'rails', '~> 6.1.6'
 gem 'sprockets', '~> 3.7.2'
 gem 'thor', '~> 1.2'
-gem 'rack', '~> 2.2.3'
+gem 'rack', '~> 2.2.4'
 
 gem 'hamlit-rails', '~> 0.2'
 gem 'pg', '~> 1.4'
@@ -40,7 +40,7 @@ end
 gem 'net-ldap', '~> 0.17'
 gem 'omniauth-cas', '~> 2.0'
 gem 'omniauth-saml', '~> 1.10'
-gem 'gitlab-omniauth-openid-connect', '~>0.9.1', require: 'omniauth_openid_connect'
+gem 'gitlab-omniauth-openid-connect', '~>0.10.0', require: 'omniauth_openid_connect'
 gem 'omniauth', '~> 1.9'
 gem 'omniauth-rails_csrf_protection', '~> 0.1'
 
@@ -78,7 +78,7 @@ gem 'rqrcode', '~> 2.1'
 gem 'ruby-progressbar', '~> 1.11'
 gem 'sanitize', '~> 6.0'
 gem 'scenic', '~> 1.6'
-gem 'sidekiq', '~> 6.4'
+gem 'sidekiq', '~> 6.5'
 gem 'sidekiq-scheduler', '~> 4.0'
 gem 'sidekiq-unique-jobs', '~> 7.1'
 gem 'sidekiq-bulk', '~> 0.2.0'