Use fixed dev-tool versions, to stabilize CI (#155)

Author: staabm

composer.json

@@ -22,9 +22,9 @@
         "phpunit/phpunit": "^9.6",
         "symfony/var-dumper": "^5.3",
         "thecodingmachine/phpstan-safe-rule": "^1.2",
-        "tomasvotruba/cognitive-complexity": "^0.2.2",
-        "tomasvotruba/type-coverage": "^0.2.0",
-        "tomasvotruba/unused-public": "^0.3.5"
+        "tomasvotruba/cognitive-complexity": "0.2.2",
+        "tomasvotruba/type-coverage": "0.2.4",
+        "tomasvotruba/unused-public": "0.3.5"
     },
     "config": {
         "optimize-autoloader": true,