fix: dont pollute lint script with grep

Signed-off-by: Bart Jaskulski <bjaskulski@protonmail.com>

includes/tests/lint.yml

@@ -7,7 +7,7 @@
     - composer install --no-dev
     - rm auth.json
   script:
-    - find -name '*.php' -print0 |xargs -n1 -0 -P16 php -l |grep -v "No syntax errors detected" && exit 1
+    - find -name '*.php' -print0 |xargs -I{} -0 -P16 php -l {} >/dev/null
 
 lint:8.3:
   extends: .lint