For users that installed OpenPanel 1.5.4 during 04-06 August, apache was automatically installed because of the libapache2-mod-php8.3 package used by ImunifyAV that pulled in apache2 as a dependency.
To resolve the issue:
bash <(curl -sSL https://raw.githubusercontent.com/stefanpejcic/OpenPanel/refs/heads/main/version/1.5.5/UPDATE.sh)