[1.21] Hot reloading to set a newly-installed font doesn't work

[DHowett]

Windows Terminal version

1.21

Windows build number

No response

Other Software

No response

Steps to reproduce

Install a new font.

Set it as the font.

Save settings.

Expected Behavior

No response

Actual Behavior

You'll get one error dialog per open terminal, and they'll switch to Consolas.

Newly-opened panes will use the specified font.

[lhecker]

It may be necessary for us to specify TRUE for GetSystemFontCollection. However, we probably don't want to do that in the startup path. Additionally, we already do that in the settings editor code so I wonder why it doesn't get triggered. Maybe it's because UpdateFontList() doesn't get called again.