Update dependency psalm/plugin-phpunit to ^0.20.0

| datasource | package              | from   | to     |
| ---------- | -------------------- | ------ | ------ |
| packagist  | psalm/plugin-phpunit | 0.18.4 | 0.20.2 |


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

Author: renovate[bot]

composer.json

@@ -44,7 +44,7 @@
         "php-amqplib/php-amqplib": "^2.0 || ^3.7.4",
         "phpunit/phpunit": "^9.6.31",
         "predis/predis": "^3.0.0",
-        "psalm/plugin-phpunit": "^0.18.4",
+        "psalm/plugin-phpunit": "^0.20.0",
         "symfony/yaml": "^6.4.26 || ^7.4.1",
         "vimeo/psalm": "^4.30.0"
     },