Fix icechunk dependency URL in bug report template

[TomNicholas]

Addresses @elyall's comment in #1463 (comment) by updating the icechunk dependency URL in the bug report template.

[ianhi]

Can we just point to the nightly wheel instead? I think that would be a better user experience. With something like this:
https://docs.astral.sh/uv/concepts/projects/dependencies/#index

it may end up being uv specific and fall back to pypi for other script runners. but that's fine with me for the convenience of not needing to compile icechunk to make a bug report.

Same for zarr I guess, though that's less important

[ianhi]

This is the magic set of settings:

        # /// script
        # requires-python = ">=3.11"
        # dependencies = [
        #   "icechunk",
        #   "zarr",
        # ]
        #
        # [[tool.uv.index]]
        # name = "scientific-python-nightly-wheels"
        # url = "https://pypi.anaconda.org/scientific-python-nightly-wheels/simple/"
        #
        # [tool.uv.sources]
        # icechunk = { index = "scientific-python-nightly-wheels" }
        # zarr = { index = "scientific-python-nightly-wheels" }
        #
        # [tool.uv]
        # prerelease = "allow"
        # ///

which does grab icechunk 2.0.0a. So we might want to constrain icechunk to be <2 for now

[TomNicholas]

Looks like you finished this @ianhi ? (Thank you!) I can't self-approve, so if you want to approve it then either of us can merge it. (Or maybe @paraseba can just give me god privileges)