add binja variant to bug report template

Author: psifertex

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,6 +9,7 @@ assignees: ''
 
 **Version and Platform (required):**
 - Binary Ninja Version: [e.g. 4.0.4000-dev] (if version is stable, please also test the latest development build via the "Update Channel" option)
+- Variant: Non-Commercial / Commercial / Ultimate
 - OS: [e.g. Ubuntu Linux]
 - OS Version: [e.g. 22.04]
 - CPU Architecture: [e.g. x64 or M1]