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
for (int k = 0; k < si.size.width; k++) {
						int h = v_offsets[k + j];
						if (h > height) {
							height = h;
							if (height > best_height) {
								break; 
							}
						}
					}
					if (height < best_height) {
						best_height = height;
						best_idx = j;
					}
				}
				
				for (int k = 0; k < si.size.width; k++) {
					v_offsets[k + best_idx] = best_height + si.size.height;
				}
				si.pos.x = best_idx;
				si.pos.y = best_height;
				if (si.pos.y + si.size.height > max_height) {
					max_height = si.pos.y + si.size.height;
				}
			}
			if (max_height <= base_size * 2) {
				atlas_height = max_height;
				break; 
			}
			base_size *= 2;
		}