Issue #3366108: Fix not being able to install project on D9

Works with Drupal 9.5.x. Testing this merge request requires a couple of changes to the installation instructions.

1. Add this fork as a repository to your project’s composer.json:

    "repositories": [
        {
            "type": "vcs",
            "url": "https://git.drupalcode.org/issue/schemadotorg_demo-3366108.git"
        },

2. Use the following Composer command to install:

composer require 'drupal/schemadotorg_demo:3366108-not-installable-9.5.x-dev@dev' -W

3. If any patches do not apply, try going to the merge requests and rebasing them.