Fix remove_tags with greater-than in quoted attributes

[deepakganesh78]

Fixes #284.

Reproduction

On current master, remove_tags('<a title="x>y">texty</a>') returns y">texty because tag matching stops at the > inside the quoted attribute value. The same happens for single-quoted attribute values.

Root cause

remove_tags used a regular expression that treated every raw > as the end of a tag. That cuts valid tags in the middle when quoted attributes contain >, leaking the tail of the opening tag into the output.

Fix

Replace the remove_tags tag regex with a small linear scanner that reads the tag name and ignores > while inside a quoted attribute value that starts after =. Quotes in unquoted attribute values keep the previous behavior, so malformed inputs such as <a b=c"d>keep</a> are still handled as before.

Compatibility notes

This changes remove_tags behavior only for valid tags whose quoted attribute values contain >. Existing which_ones and keep filtering is preserved.

Validation

• Regression check with the fix reverted: python -m pytest tests\test_html.py::TestRemoveTags::test_remove_tags_with_gt_in_quoted_attribute tests\test_html.py::TestRemoveTags::test_remove_tags_with_unquoted_quote_in_attribute -q -> 1 failed, 1 passed (expected failure: y">texty vs texty).
• Targeted tests: python -m pytest tests\test_html.py::TestRemoveTags -q -> 11 passed.
• Full test suite: python -m pytest -> 409 passed, 4 skipped, 74 xfailed.
• Lint on touched files: python -m ruff check w3lib\html.py tests\test_html.py -> all checks passed.
• Formatting check on touched files: python -m ruff format --check w3lib\html.py tests\test_html.py -> 2 files already formatted.
• Type check: python -m mypy w3lib tests -> success, no issues in 20 source files.

[codecov]

Codecov Report

❌ Patch coverage is 92.72727% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 98.11%. Comparing base (8d10401) to head (e5fbddf).
⚠️ Report is 47 commits behind head on master.

Files with missing lines	Patch %	Lines
w3lib/html.py	92.72%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #294      +/-   ##
==========================================
- Coverage   98.47%   98.11%   -0.37%     
==========================================
  Files           9        9              
  Lines         853      902      +49     
  Branches      177      193      +16     
==========================================
+ Hits          840      885      +45     
- Misses          5        7       +2     
- Partials        8       10       +2     

Files with missing lines	Coverage Δ
w3lib/html.py	97.57% <92.72%> (-2.43%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[codspeed-hq]

Merging this PR will not alter performance

✅ 45 untouched benchmarks

---

_{Comparing deepakganesh78:fix/issue284-remove-tags-quoted-gt (e5fbddf) with master (8d10401)}