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
RenderTarget *rt = render_target_owner.get_or_null(p_render_target);
	ERR_FAIL_COND_V(!rt, Size2i());
	return rt->size;
}
void TextureStorage::render_target_set_override(RID p_render_target, RID p_color_texture, RID p_depth_texture, RID p_velocity_texture) {
	RenderTarget *rt = render_target_owner.get_or_null(p_render_target);
	ERR_FAIL_COND(!rt);
	ERR_FAIL_COND(rt->direct_to_screen);
	rt->overridden.velocity = p_velocity_texture;
	if (rt->overridden.color == p_color_texture && rt->overridden.depth == p_depth_texture) {
		return;
	}
	if (p_color_texture.is_null() && p_depth_texture.is_null()) {
		_clear_render_target(rt);
		_update_render_target(rt);
		return;
	}
	if (!rt->overridden.is_overridden) {
		_clear_render_target(rt);
	}
	rt->overridden.color = p_color_texture;
	rt->overridden.depth = p_depth_texture;
	rt->overridden.is_overridden = true;
	uint32_t hash_key = hash_murmur3_one_64(p_color_texture.get_id());
	hash_key = hash_murmur3_one_64(p_depth_texture.get_id(), hash_key);
	hash_key = hash_fmix32(hash_key);