Only match comments for the current block node

Note: comments can span multiple lines, so check against all lines.

lib/rubocop/cop/obsession/rails/safety_assured_comment.rb

@@ -41,11 +41,9 @@ class SafetyAssuredComment < Base
 
           def on_block(node)
             return if !safety_assured_block?(node)
-            previous_comment = processed_source.comments_before_line(node.first_line)&.last
+            comment = processed_source.ast_with_comments[node].map(&:text).join("\n")
 
-            if previous_comment.nil? || !previous_comment.text.match?(/^# Safe because( [^ ]+){4}/)
-              add_offense(node)
-            end
+            add_offense(node) if !comment.match?(/^# Safe because( [^ ]+){4}/)
           end
         end
       end