Less tight caps

Alternative set of buttons for [Not-So-Slimbox](https://www.thingiverse.com/thing:5349287), in case your printer cant be precise enough tolerancewise.
Main differences:
- Wall thickness reduced by 0.25mm, adding roughly 1 layer worth of space between it and the housing
- Stem cross opening enlarged symmetrically by 0.25mm, adding more space for the stem of the switch to fit in (wobble-galore on my printer, but at least it fits)
- Stem pillar OD decreased by 0.1mm, to influence slicers to round it up to the smaller side

## Note!
The caps are supposed to be super tight on the stem, since it's the only thing keeping them in place from flying out when releasing the button. Unfortunately, these kinds of sub-millimeter tolerances are not consistent between printers or even slicer settings, so do try and fit the original ones first :)