Allow Drupal 12 in composer.json to match the info.yml core requirement

Problem/Motivation

Follow-up to #3629649 (thanks podarok). Bootstrap Styles 1.2.5 declares core_version_requirement: ^10.3 || ^11 || ^12 in its info.yml, but composer.json still requires "drupal/core": "^10.3 || ^11". packages.drupal.org takes the core requirement from composer.json, so Composer refuses 1.2.5 on Drupal 12.

Steps to reproduce

1. In an empty project using packages.drupal.org, PHP 8.5, run composer require drupal/core-recommended:^12@alpha drupal/bootstrap_styles:1.2.5
2. Composer stops with drupal/bootstrap_styles 1.2.5 requires drupal/core ^10.3 || ^11.

Proposed resolution

Change composer.json to "drupal/core": "^10.3 || ^11 || ^12". Nothing else: drupal/media_library_form_element 2.1.5 already allows ^12, so the existing ^2.0 constraint resolves on Drupal 12.

Remaining tasks

• ✅ File an issue
• ✅ Addition/Change/Update/Fix
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support
• ➖ User Guide Documentation support
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes
• ✅ Release

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Composer now accepts Bootstrap Styles 1.2.x on Drupal 12.