Unpin packages in default dashboard env

[iameskild]

Reference Issues or PRs

Fixes #1617

What does this implement/fix?

This simply unpins the packages used by the default nebari-git/dashboard environment. It was originally pinned because the solve was taking a long time but with the switch to using mamba to build these environments, that hasn't been an issue. Our other default environment nebari-git/dask already has it's packages unpinned.

Put a x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds a feature)
• Breaking change (fix or feature that would cause existing features not to work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other (please describe):

Testing

• Did you test the pull request locally?
• Did you add new tests?

Any other comments?

[kcpevey]

I dont think these should be left unpinned. That said, Pam and I have been working on updating the dashboard examples which is also requiring an update to this environment. So, I'm approving this to get this bug fixed, but I'll follow up with a PR which will make improvements on it (not to be included in this release).