Update dependency psalm/plugin-phpunit to ^0.20.0

| datasource | package              | from   | to     |
| ---------- | -------------------- | ------ | ------ |
| packagist  | psalm/plugin-phpunit | 0.19.7 | 0.20.1 |


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

Author: renovate[bot]

composer.json

@@ -43,7 +43,7 @@
         "mikey179/vfsstream": "^1.6.12",
         "phpbench/phpbench": "^1.2.7",
         "phpunit/phpunit": "^11.0",
-        "psalm/plugin-phpunit": "^0.18.0 || ^0.19.0",
+        "psalm/plugin-phpunit": "^0.20.0",
         "squizlabs/php_codesniffer": "^3.7.1",
         "vimeo/psalm":"^6.0"
     },