Regression from #71248:

I believe this pull may have caused errors on WebGL since it moves the `GLES_OVER_GL` guard. WebGL does not support texture swizzling per: https://registry.khronos.org/webgl/specs/latest/2.0/#5.19
so this is causing the following trace in Chrome:
```
WebGL: INVALID_ENUM: texParameter: invalid parameter name
```
and it quickly fills up the 256 log limit for the same message in WebGL.

This doesn't appear to be breaking anything asides from causing the numerous log messages.

_Originally posted by @jnlopar in https://github.com/godotengine/godot/issues/71248#issuecomment-1384768973_

CC @rsjtdrjgfuzkfg @clayjohn
Size2i margin;
	int scale;
	switch (rt->sdf_oversize) {
		case RS::VIEWPORT_SDF_OVERSIZE_100_PERCENT: {
			scale = 100;
		} break;
		case RS::VIEWPORT_SDF_OVERSIZE_120_PERCENT: {
			scale = 120;
		} break;
		case RS::VIEWPORT_SDF_OVERSIZE_150_PERCENT: {
			scale = 150;
		} break;
		case RS::VIEWPORT_SDF_OVERSIZE_200_PERCENT: {
			scale = 200;
		} break;
		default: {
		}
	}
	margin = (rt->size * scale / 100) - rt->size;
	Rect2i r(Vector2i(), rt->size);
	r.position -= margin;
	r.size += margin * 2;
	return r;
}
Rect2i TextureStorage::render_target_get_sdf_rect(RID p_render_target) const {