[slottable-request] Given that `remove` is a short, common identifier, we may want to consider exposing this as a static symbol like `SlottableRequestEvent.remove`.

Given that `remove` is a short, common identifier, we may want to consider exposing this as a static symbol like `SlottableRequestEvent.remove`. _Originally posted by @hunterloftis in https://github.com/webcomponents-cg/community-protocols/pull/45#discussion_r1511455050_