Missing Montserrat and OpenSans fonts for `ui_flexbox` demo, causes endless error spam

[akien-mga]

Trying to open the current main version aace8be370696a7719b6f6c93081a73ae412e2ec in Godot 4.0-rc (6cde3fac328e97e66b1c12d386deb25af395e215):

ERROR: Resource file not found: res://assets/fonts/Montserrat-Bold.ttf.
   at: _load (core/io/resource_loader.cpp:226)
ERROR: res://ui_flexbox/assets/fonts/font_title_small.tres:9 - Parse Error: [ext_resource] referenced non-loaded resource at: res://assets/fonts/Montserrat-Bold.ttf
   at: _parse_ext_resource (scene/resources/resource_format_text.cpp:174)
ERROR: res://ui_flexbox/assets/fonts/font_title_small.tres:9 - Parse Error: [ext_resource] referenced non-loaded resource at: res://assets/fonts/Montserrat-Bold.ttf
   at: load (scene/resources/resource_format_text.cpp:735)
ERROR: Failed loading resource: res://ui_flexbox/assets/fonts/font_title_small.tres. Make sure resources have been imported by opening the project in the editor at least once.
   at: _load (core/io/resource_loader.cpp:221)
ERROR: Condition "sampled_font.is_null()" is true. Returning: Ref<Texture2D>()
   at: generate_from_path (editor/plugins/editor_preview_plugins.cpp:802)

Repeats ad lib.

[akien-mga]

Seems like there's a bunch more missing:

• Montserrat-Bold.ttf
• Montserrat-Regular.ttf
• OpenSans-Bold.ttf
• OpenSans-BoldItalic.ttf
• OpenSans-Italic.ttf
• OpenSans-Regular.ttf

[akien-mga]

I see the files are in ui_flexbox/assets/fonts/, it was probably authored as a standalone demo and not fully ported to run as part of the collection of demos.