Fix(CI): phpstan (#109)

phpstan.neon

@@ -1,6 +1,9 @@
+includes:
+    - ../../vendor/glpi-project/phpstan-glpi/extension.neon
+    - ../../vendor/phpstan/phpstan-deprecation-rules/rules.neon
+    - ../../vendor/thecodingmachine/phpstan-safe-rule/phpstan-safe-rule.neon
+
 parameters:
-    parallel:
-        maximumNumberOfProcesses: 2
     level: 5
     paths:
         - front
@@ -10,10 +13,12 @@ parameters:
         - setup.php
         - stat.php
     scanDirectories:
-        - ../../inc
         - ../../src
-        - ../../front
     bootstrapFiles:
         - ../../stubs/glpi_constants.php
         - ../../vendor/autoload.php
-
+        - setup.php
+    treatPhpDocTypesAsCertain: false
+    ignoreErrors:
+        - message: "#.*always true#"
+        - message: "#Unreachable statement#"