build: hard dependencies (#184)

Author: Greg Bowler

composer.json

@@ -9,8 +9,8 @@
 		"magicalex/write-ini-file": "v1.2.4"
 	},
 	"require-dev": {
-		"phpunit/phpunit": "9.*",
-		"phpstan/phpstan": ">=0.12.64"
+		"phpstan/phpstan": "v1.8.0",
+		"phpunit/phpunit": "v9.5.21"
 	},
 
 	"license": "MIT",
@@ -43,4 +43,4 @@
 			"Gt\\Config\\Test\\": "./test/phpunit"
 		}
 	}
-}
+}