Bump phpstan/phpstan from 1.12.32 to 2.1.32 in /tools/phpstan

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-version: 2.1.32
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tools/phpstan/composer.json

@@ -3,7 +3,7 @@
   "description": "Aeon PHP Calendar - Tools",
   "require-dev": {
     "php": "~8.2.0 || ~8.3.0 || ~8.4.0 || ~8.5.0",
-    "phpstan/phpstan": "^1.1.2"
+    "phpstan/phpstan": "^2.1.32"
   },
   "config": {
     "allow-plugins": false