Remove gitlab ci file as it gets pushed by the packagist integration

.gitlab-ci.yml

-Deploy:
-  script:
-    - curl -XPOST -H'content-type:application/json' "https://packagist.org/api/update-package?username=${PACKAGIST_USERNAME}&apiToken=${PACKAGIST_API_TOKEN}" -d'{"repository":{"url":"'${CI_PROJECT_URL}'"}}'