CI - temporarily disable security-checker

https://github.com/sensiolabs/security-checker
Jan 15 2021 WARNING: Don't use this piece of software anymore as the underlying web service will stop working at the end of January 2021.

Author: zdenekdrahos

tests/.travis/.phpqa.yml

@@ -21,7 +21,7 @@ phpqa:
         - phpstan
         - phpunit:0
         - psalm
-        - security-checker:0
+        - security-checker
         - parallel-lint:0
 
 phpcs: