Add Heisenbug 2026 Spring conference (#838)

* Initial plan

* Add Heisenbug 2026 Spring conference

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

* Add registration status for Heisenbug 2026 Spring

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

* Fix chronological ordering - place STAREAST before Heisenbug

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

Author: Copilot

_data/current.yml

@@ -133,6 +133,12 @@
   twitter: TechWell
   status: <a href="https://stareast.techwell.com/pricing-packages?utm_source=testingconferences" target="_blank">Super Early Bird Pricing is Open</a> until February 27, 2026
 
+- name: Heisenbug 2026 Spring
+  location: Moscow, Russia and Online
+  dates: "April 27-28, 2026"
+  url: https://heisenbug.ru/en/?utm_source=testingconferences
+  status: <a href="https://heisenbug.ru/en/registration/personal/?utm_source=testingconferences" target="_blank">Registration is Open</a>
+
 - name: Romania QualityConnect 2026
   location: Cluj-Napoca, Romania
   dates: "May 6-7, 2026"