Replace try with safe navigation operator

Try looks for method defined, but we know the method is defined if the attriute is present.

app/models/embed/purl/resource_file.rb

@@ -77,7 +77,7 @@ def image?
 
       # @return [Integer]
       def size
-        @file.attributes['size'].try(:value).to_i
+        @file.attributes['size']&.value.to_i
       end
 
       # unused (9/2016) - candidate for removal?