[6.2.x] Drupal 11.2.x ModuleInstaller changes break WxT sub-module installs

I get the same error when installing via the UI:

Looks like LocalGov Drupal folks are also running into this issue, which might be caused by differences between 11.1.x and 11.2.x, see related issue.

Adding parent issue where this regression originated.

Here is my summary of the changes and how they impact WxT:

It looks like Drupal 11.2.x introduced major changes to how module configuration is validated and installed:

1. Modules are now validated and installed in batches, not individually. This means all default config across a group of modules is validated together before any of them install. If one module references a bundle/config provided by another module, and that config is in /config/optional or not present in the install profile's exported config, the entire batch now fails validation.
2. Config install is now split into phases: InstallSimple -> InstallEntities -> Optional. Bundles placed in /config/optional don’t get created until the "Optional" phase, which now runs after entity display and field config that depends on those bundles. This exposes hidden ordering problems that used to work by accident (and were always a bit finicky).
3. Profile-based installs no longer see a module's /config/install as part of the "initial config set". If a distribution rewrites config from contrib modules (e.g., Metatag) but the profile does not export that base config, config_rewrite now reports "initial config missing".

For Drupal WxT, we have several profile extensions that are optionally enabled (e.g., wxt_ext_metatag adjusts Metatag defaults to align with Government of Canada standards). With these installer changes, it appears we can no longer rely on optional profile modules to safely provide or rewrite configuration. We may now need to declare more dependencies directly on the profile itself, making the configuration more "all or nothing".

Might be time to consider other options like recipes, or remove "optional" modules and just install everything. I think to get this working now, we would need to add all sub-module dependencies on the profile itself.