Merge branch 'fix-inline-filter-speed' into 'master'
Fix serious performance bug with rendering Markdown with InlineDiffFilter Nokogiri's `node.replace` was being unnecessarily called for every text node in the document due to a comparison bug. The code previously was comparing the HTML representation of the full document against the text node, which would always fail. Fix the comparison to just compare the modified text. Closes #18011 See merge request !4392