BUG: Fix for pd.read_fwf not reading addinfourl object
- [x] closes #26376 
- [ ] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

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Not sure, how to add a new test for this particular case. Is it is possible without creating a `addinfourl` object with a specific URL? Thanks.
