Update dependency psalm/plugin-phpunit to ^0.20.0

| datasource | package              | from   | to     |
| ---------- | -------------------- | ------ | ------ |
| packagist  | psalm/plugin-phpunit | 0.19.6 | 0.20.0 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

composer.json

@@ -39,7 +39,7 @@
         "laminas/laminas-stdlib": "^3.20",
         "phpbench/phpbench": "^1.3.1",
         "phpunit/phpunit": "^10.5.58",
-        "psalm/plugin-phpunit": "^0.19.0",
+        "psalm/plugin-phpunit": "^0.20.0",
         "psr/container": "^1.1.2 || ^2.0.2",
         "sebastian/recursion-context": "^5.0.1",
         "vimeo/psalm": "^6.13"