I think bold is the least fitting font weight for inlay hints, which
should be subtle hints and not, well, bold.

If someone feels strongly about this, I can revert, but only if we add
the ability to change this per theme.

Until then: beautiful, thin, subtle inlay hints!

Release Notes:

- Improved styling of inlay hints by not making them bold in the editor.


![screenshot-2024-02-23-17 30
29@2x](https://github.com/zed-industries/zed/assets/1185253/89c2a162-76bb-45cd-8b45-2a5bdf8ca87b)