Initialize static files' data hash only if needed (#8188)

Merge pull request 8188

lib/jekyll/static_file.rb

@@ -4,7 +4,7 @@ module Jekyll
   class StaticFile
     extend Forwardable
 
-    attr_reader :relative_path, :extname, :name, :data
+    attr_reader :relative_path, :extname, :name
 
     def_delegator :to_liquid, :to_json, :to_json
 
@@ -34,7 +34,6 @@ module Jekyll
       @collection = collection
       @relative_path = File.join(*[@dir, @name].compact)
       @extname = File.extname(@name)
-      @data = @site.frontmatter_defaults.all(relative_path, type)
     end
     # rubocop: enable Metrics/ParameterLists
 
@@ -113,6 +112,10 @@ module Jekyll
       true
     end
 
+    def data
+      @data ||= @site.frontmatter_defaults.all(relative_path, type)
+    end
+
     def to_liquid
       @to_liquid ||= Drops::StaticFileDrop.new(self)
     end