chore: release v15.12.0 (#33459)

* chore: release v15.12.0

* Apply suggestion from @mschile

---------

Co-authored-by: Matt Schile <mschile@cypress.io>

Author: cacieprins

cli/CHANGELOG.md

@@ -1,7 +1,8 @@
 <!-- See the ../guides/writing-the-cypress-changelog.md for details on writing the changelog. -->
+
 ## 15.12.0
 
-_Released 03/10/2026 (PENDING)_
+_Released 03/10/2026_
 
 **Features:**
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "cypress",
-  "version": "15.11.0",
+  "version": "15.12.0",
   "description": "Cypress is a next generation front end testing tool built for the modern web",
   "private": true,
   "scripts": {