Change renderer to GL Compatibility

Godot 4 new default is Forward+, but we don't seem to require any
features from that, so switch to the most compatible choice instead.

Test
* win64 editor build. run and jump around and it looks the same as
  before.

2d/skeleton/README.md

@@ -6,7 +6,7 @@ there is a simple character controller that controls the animations.
 
 Language: GDScript
 
-Renderer: GLES 2
+Renderer: GL Compatibility
 
 Check out this demo on the asset library: https://godotengine.org/asset-library/asset/1027
 

2d/skeleton/project.godot

@@ -77,6 +77,8 @@ limits/debugger_stdout/max_chars_per_second=1000000
 
 [rendering]
 
+renderer/rendering_method="gl_compatibility"
+renderer/rendering_method.mobile="gl_compatibility"
 quality/driver/driver_name="GLES2"
 2d/snapping/use_gpu_pixel_snap=true
 vram_compression/import_etc=true