Update Drupal 10 references to Drupal 11 in the welcome tour and default content

Problem/Motivation

The welcome tour modal (varbase_tour) and a default content block still say Drupal 10 ('Varbase is the ultimate Drupal 10 starter kit' and a Webform block mentioning 'for Drupal 10'). On the 9.2.x line Varbase only supports Drupal 11.

Steps to reproduce

Proposed resolution

Update the two Drupal 10 text mentions to Drupal 11 in modules/varbase_tour/templates/welcome-modal.html.twig and the default content block YAML.

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_core-9.2.0

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Released in varbase_core-9.2.0