Wrong font weights on some component demo pages

[ashetland]

Description

On a local build, some component pages show incorrect font weights. These overrides should be removed so components are accurately represented. For example, the pages for Combobox, Input Time Zone, and Tree show medium font weights everywhere instead of only on selected items. Other pages may also be affected.

Wrong weights shown on Tree page:

Correct weights shown on Tree Scales page:

Which Component

Combobox
Input Time Zone
Tree
Possibly others

Resources

No response

[macandcheese]

Tree is a bit of an outlier compared to similar components like List, etc, because Tree Item label content is slotted in. We could look at accepting a labelText prop or something to have more standardization - the examples above with links could still be supported with a slot?

[ashetland]

I used Tree as an example because it was simpler to show, but this is how Combobox and Input Time Zone appear on the demo pages:

cc @anveshmekala