BUG: Recognize chained fsspec URLs
- [ ] closes #48978
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.

The new `(::[A-Za-z0-9+\-+.]+)*` part of the regex will allow for optional `::<alphanumeric+-.>`-like strings  before the `://` section of the URL, which will enable it to recognize chained fsspec URLs.
Just confirming that there isn't a solution alluded to in https://github.com/pandas-dev/pandas/issues/48978#issuecomment-1813692546 where `fsspec` provides an API already to validate fsspec URLs? > Just confirming that there isn't a solution alluded to in [#48978 (comment)](https://github.com/pandas-dev/pandas/issues/48978#issuecomment-1813692546) where `fsspec` provides an API already to validate fsspec URLs?

I checked the latest fsspec API reference and couldn't find any public functions for validating URLs.
https://filesystem-spec.readthedocs.io/en/latest/api.html
 Thanks @snitish  Thanks @snitish!

I thought the bug was going to get closed the same week as when I documented the root cause and the bullet point solution.  Took a few years in the end! Wow, I filed this bug in October 2022.  I am super pleased to have it fixed.  It would be churlish to complain about the amount of time it's taken--instead, I am just impressed by how inexorable progress seems to be! Thanks @JMBurley for the outline you provided - it helped me fix this bug in no time.
@ligon glad I could be of help  :) Could this fix also be applied to 2.3.x ?