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
if (p_image->is_compressed()) {
			ERR_PRINT("Texture '" + texture->path + "' is required to be a power of 2 because it uses either mipmaps or repeat, so it was decompressed. This will hurt performance and memory usage.");
		}
		if (img == p_image) {
			img = img->duplicate();
		}
		img->resize_to_po2(false);
	}
	GLenum blit_target = (texture->target == GL_TEXTURE_CUBE_MAP) ? _cube_side_enum[p_layer] : texture->target;
	Vector<uint8_t> read = img->get_data();
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(texture->target, texture->tex_id);
	
	texture->gl_set_filter(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST);
	texture->gl_set_repeat(RS::CANVAS_ITEM_TEXTURE_REPEAT_ENABLED);
	switch (texture->format) {
#ifdef GLES_OVER_GL
		case Image::FORMAT_L8: {
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_R, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_G, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_B, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_ONE);
		} break;
		case Image::FORMAT_LA8: {
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_R, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_G, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_B, GL_RED);
			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_GREEN);
		} break;
#endif