Remove the dead includes/helpers.inc include from varbase_auth.install (file deleted in the OOP hooks conversion)

Problem/Motivation

varbase_auth.install still contains include_once __DIR__ . '/includes/helpers.inc';. During the OOP hooks conversion, includes/helpers.inc was deleted and its functions were moved into the module's #[Hook] class, but the dead include line in the .install file was not removed.

This causes a PHP warning on install/rebuild:

Warning: include_once(): Failed opening '.../varbase_auth/includes/helpers.inc' for inclusion ... varbase_auth.install:12

Steps to reproduce

Install or rebuild a site with varbase_auth (10.1.x) enabled and observe the include warning referencing includes/helpers.inc at varbase_auth.install:12.

Proposed resolution

Remove the dead include_once __DIR__ . '/includes/helpers.inc'; line from varbase_auth.install, keeping the includes/updates.inc include.

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-10.1.1, varbase_auth-10.1.1

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A