`regolith watch` is broken in certain conditions

[Nusiq]

~~I don't know what causes the problem yet but here are some details about the project:~~

• ~~I'm on Windows~~
• ~~My project only has resource pack~~
• ~~My export target is development~~
• ~~My project is on the same drive as the export target (C: drive)~~
• ~~My project is saved almost directly in C: directory~~

Update: Adding a file to packs/BP folder fixes the problem. It seems that regolith watch doesn't work if you have only resource pack in the project.