Just like the manual a2enmod the following resolves the situation as well as now the old mod-php7.2 is "out-of-the-way".
$ apt install --reinstall libapache2-mod-php7.3
Just like the manual a2enmod the following resolves the situation as well as now the old mod-php7.2 is "out-of-the-way".
$ apt install --reinstall libapache2- mod-php7. 3