[fix] utils: truncated result (#4949)

Make sure to prase everything before returning.

Related: \
```
FAIL: test_html_to_text (tests.unit.test_utils.TestUtils.test_html_to_text)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/searxng/searxng/tests/unit/test_utils.py", line 53, in test_html_to_text
    self.assertEqual(utils.html_to_text(r"regexp: (?<![a-zA-Z]"), "regexp: (?<![a-zA-Z]")
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'regexp: (?' != 'regexp: (?<![a-zA-Z]'
- regexp: (?
+ regexp: (?<![a-zA-Z]
```

searx/utils.py

@@ -161,9 +161,11 @@ def html_to_text(html_str: str) -> str:
     s = _HTMLTextExtractor()
     try:
         s.feed(html_str)
+        s.close()
     except AssertionError:
         s = _HTMLTextExtractor()
         s.feed(escape(html_str, quote=True))
+        s.close()
     except _HTMLTextExtractorException:
         logger.debug("HTMLTextExtractor: invalid HTML\n%s", html_str)
     return s.get_text()