Pin w3lib version as requirement (or update library to be able to use newest w3lib versions)

[rennerocha]

w3lib 2.3.0 removed to_native_str (https://github.com/scrapy/w3lib/releases/tag/v2.3.0) function. So we are unable to use the latest version of this library now:

  File "./.venv/lib/python3.10/site-packages/frontera/core/models.py", line 3, in <module>
    from w3lib.util import to_bytes, to_native_str
ImportError: cannot import name 'to_native_str' from 'w3lib.util' (./.venv/lib/python3.10/site-packages/w3lib/util.py)

[Gallaecio]

@rennerocha Are you using only frontera, or scrapy-frontera as well? I’m looking for people to test the combination of scrapinghub/scrapy-frontera#14 and #416 on real code before merging and releasing, since the test coverage of https://github.com/scrapinghub/scrapy-frontera does not give me much confidence.

[Gallaecio]

#418