Symfony Mailer plugin still expected after submodule uninstall

Problem/Motivation

When the symfony mailer reroute submodule is uninstalled, it should also remove itself from all symfony mailer configurations, otherwise uninstallation works as expected, but the symfony mailer configuration is broken and the symfony mailer administration page shows an error:

Drupal\Component\Plugin\Exception\PluginNotFoundException: The "reroute_email" plugin does not exist.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes