Set an upper bound on NGLView so that ipywidgets v7 is usable

[github-actions[bot]]

:point_left: Launch a binder notebook on branch _pyiron/ironflow/nglviewpin

[coveralls]

Pull Request Test Coverage Report for Build 7493132314

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+16.2%) to 66.983%

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Totals
Change from base Build 6430203420:	16.2%
Covered Lines:	4301
Relevant Lines:	6421

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💛 - Coveralls