Fix inline HTML case

[facelessuser]

HTML handling is inconsistent. In some places it allows < and > in attributes, and in other places rejects it.

The HTML spec allows for these in attributes, and browsers will escape them. While it is generally recommended that users escape < and >, it is not explicitly required.

If the attribute is quoted, it should allow < and >.

Update regex pattern to allow attributes with angled brackets and use possessive quantifiers for performance as we are now only supporting Python 3.10+.

Fixes #1647

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