SCons 4.2.0 reports warning message: "Calling missing SConscript without error is deprecated"

[Calinou]

Godot version

4.0.dev (7ab78c4)

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 470.57.02)

Issue description

scons: warning: Calling missing SConscript without error is deprecated.
Transition by adding must_exist=False to SConscript calls.

Steps to reproduce

Run scons in the Godot root directory with SCons 4.2.0 or later.

Minimal reproduction project

N/A

[bruvzg]

Missing SConscript is probably modules/gdnative/xr/SCsub which was removed in #52003, but still listed in the modules/gdnative/SCsub.

[Xrayez]

The must_exist=False is useful for optional user modules (lets say we have a game module which users could copy-paste directly into Godot source, and Godot would call SConstript("game/SCSub", must_exist=False). But Godot does not use nor support this kind of approach so all calls to non-existing SCSub with hardcoded paths should likely be removed.