Start a 9.2.x branch for Varbase Media Header to support Drupal ~11.4 and drop support for Drupal ~10

Problem/Motivation

Varbase 9.2.x is the Drupal ~11.4-only continuation of the 9.1.x line (drops Drupal 10). Varbase Media Header needs a matching 9.2.x branch that targets Drupal ~11.4 only and no longer pins vardot/varbase-patches (patches are project-level in vardot/varbase-project).

Steps to reproduce

Proposed resolution

Cut 9.2.x off 9.1.x. Set core_version_requirement and drupal/core to ~11.4.0 only (drop ~10.6.0 || ~11.3.0). Require drupal/varbase_media ~9.2. Remove the vardot/varbase-patches requirement.

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ 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 varbase-9.2.0, varbase_media_header-9.2.0

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A