package/rtl8723bu: fix module installation

At the moment module is build but not installed to target/. To fix this
let's bump package to 2023-02-18 version on master branch to fix module
installation.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>