`solara.Meta` adds an empty span to DOM

[iisakkirotko]

This can have unexpected consequences for spacing when, for instance, using flex-boxes with a set gap, like the ones that are automatically added if an element has more than one direct child.

An example issue can be found in the linked PR

[maartenbreddels]

I think we should check all empty spans, and make sure we are compatible with ipyvue < 1.11.0 https://github.com/widgetti/ipyvue/pull/92