fix: address remaining Copilot review comments on PR #284

- Use $userName instead of $roleName in ALTER USER (CreateProjectHandler)
- Add JSON_THROW_ON_ERROR to json_decode in ABS/SourceFile (mirrors S3 fix)
- Restore phpstan-phpunit extension includes in 3 packages
- Restore phpstan-symfony extension include in driver-common

Author: zajca

phpstan.neon

@@ -16,4 +16,5 @@ parameters:
             path: src/Connection/Snowflake/*
             reportUnmatched: false
 includes:
+    - vendor/phpstan/phpstan-phpunit/extension.neon
     - phpstan-baseline.neon