Optimize map { ... }.compact calls (#15513)

* Optimize map { ... }.compact

using Enumerable#filter_map, supported since Ruby 2.7

* Add poyfill for Enumerable#filter_map

app/models/status.rb

@@ -334,7 +334,7 @@ class Status < ApplicationRecord
     def from_text(text)
       return [] if text.blank?
 
-      text.scan(FetchLinkCardService::URL_PATTERN).map(&:first).uniq.map do |url|
+      text.scan(FetchLinkCardService::URL_PATTERN).map(&:first).uniq.filter_map do |url|
         status = begin
           if TagManager.instance.local_url?(url)
             ActivityPub::TagManager.instance.uri_to_resource(url, Status)
@@ -343,7 +343,7 @@ class Status < ApplicationRecord
           end
         end
         status&.distributable? ? status : nil
-      end.compact
+      end
     end
   end