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
glClear(GL_COLOR_BUFFER_BIT);
	CopyEffects::get_singleton()->copy_to_rect(Rect2i(0, 0, 1.0, 1.0));
	glReadPixels(0, 0, texture->alloc_width, texture->alloc_height, GL_RGBA, GL_UNSIGNED_BYTE, &w[0]);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glDeleteTextures(1, &temp_color_texture);
	glDeleteFramebuffers(1, &temp_framebuffer);
	data.resize(data_size);
	ERR_FAIL_COND_V(data.size() == 0, Ref<Image>());
	Ref<Image> image = Image::create_from_data(texture->width, texture->height, false, Image::FORMAT_RGBA8, data);
	ERR_FAIL_COND_V(image->is_empty(), Ref<Image>());
	if (texture->format != Image::FORMAT_RGBA8) {
		image->convert(texture->format);
	}
	if (texture->mipmaps > 1) {
		image->generate_mipmaps();
	}
#endif
#ifdef TOOLS_ENABLED
	if (Engine::get_singleton()->is_editor_hint() && !texture->is_render_target) {
		texture->image_cache_2d = image;
	}
#endif
	return image;
}
void TextureStorage::texture_replace(RID p_texture, RID p_by_texture) {
	Texture *tex_to = texture_owner.get_or_null(p_texture);
	ERR_FAIL_COND(!tex_to);
	ERR_FAIL_COND(tex_to->is_proxy); 
	Texture *tex_from = texture_owner.get_or_null(p_by_texture);
	ERR_FAIL_COND(!tex_from);