[TRACKING] Only building images for Godot 4.2

[AngelOnFira]

Currently, we only build images for Godot 4.2. This is for a few reasons:

• The Rivet plugin only supports Godot 4.2. When changing to older versions, some syntax isn't allowed.
• There are some inconsistencies when downloading the files needed for older versions of Godot.
• Reducing the amount of noise from other images that won't be used for now.

This tracking issue will be updated as blockers for more versions are resolved.