Move the line to 0.6

The cache no longer keeps its own clock, which is a break, so the whole stack takes one
number rather than leaving each package on a version of its own.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ARqBYLxrHqevcVmxHkpJcZ

Author: Radoslaw Ziemniewicz

composer.json

@@ -32,11 +32,11 @@
     },
     "require-dev": {
         "phpstan/phpstan": "^2.0",
-        "quillstack/unit-tests": "^0.8"
+        "quillstack/unit-tests": "^0.9"
     },
     "extra": {
         "branch-alias": {
-            "dev-main": "0.5.x-dev"
+            "dev-main": "0.6.x-dev"
         }
     },
     "scripts": {