chore(MSP-5160): run phpstan under Infection as a mutant killer, in addition to PHPUnit

See https://infection.github.io/guide/static-analysis-integration.html

In a nutshell: this will help killing more mutants if they violate PHPStan rules but don't trigger PHPUnit tests failures

Author: maks-rafalko

composer.json

@@ -59,7 +59,7 @@
       "@lint:php"
     ],
     "phpstan": [
-      "phpstan analyse --memory-limit=-1 src/ tests/ rector.php --ansi --no-progress"
+      "phpstan analyse --memory-limit=-1 --ansi --no-progress"
     ],
     "rector:check": [
       "rector --dry-run --ansi --no-progress-bar"

infection.json5

@@ -8,5 +8,6 @@
   "mutators": {
     "@default": true
   },
-  "maxTimeouts": 0
+  "maxTimeouts": 0,
+  staticAnalysisTool: 'phpstan'
 }

phpstan.neon

@@ -5,9 +5,13 @@ includes:
   - phar://vendor/phpstan/phpstan/phpstan.phar/conf/bleedingEdge.neon
 
 parameters:
+    paths:
+        - ./src
+        - ./tests
+        - ./rector.php
     level: max
     reportUnmatchedIgnoredErrors: false
     checkExplicitMixed: true
- 
+
     ignoreErrors:
         - '#Dynamic call to static method PHPUnit\\Framework\\.*#'