Worst case quadratic complexity in HTMLParser

[serhiy-storchaka]

Linked PRs

• gh-135462: Fix quadratic complexity in processing special input in HTMLParser #135464
• [3.14] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135481
• [3.13] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135482
• [3.12] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135483
• [3.11] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135484
• [3.10] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135485
• [3.9] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) #135486