Drop magic-public-key from webfinger replies as it's only used for OStatus (mastodon#11280)

Author: ClearlyClaire

app/serializers/webfinger_serializer.rb

@@ -18,7 +18,6 @@ def links
       { rel: 'http://webfinger.net/rel/profile-page', type: 'text/html', href: short_account_url(object) },
       { rel: 'http://schemas.google.com/g/2010#updates-from', type: 'application/atom+xml', href: account_url(object, format: 'atom') },
       { rel: 'self', type: 'application/activity+json', href: account_url(object) },
-      { rel: 'magic-public-key', href: "data:application/magic-public-key,#{object.magic_key}" },
       { rel: 'http://ostatus.org/schema/1.0/subscribe', template: "#{authorize_interaction_url}?uri={uri}" },
     ]
   end

app/views/well_known/webfinger/show.xml.ruby

@@ -25,11 +25,6 @@ doc << Ox::Element.new('XRD').tap do |xrd|
     link['href']     = account_url(@account)
   end
 
-  xrd << Ox::Element.new('Link').tap do |link|
-    link['rel']      = 'magic-public-key'
-    link['href']     = "data:application/magic-public-key,#{@account.magic_key}"
-  end
-
   xrd << Ox::Element.new('Link').tap do |link|
     link['rel']      = 'http://ostatus.org/schema/1.0/subscribe'
     link['template'] = "#{authorize_interaction_url}?acct={uri}"