removed outdated gitlab ci file

.gitlab-ci.yml

@@ -1,20 +0,0 @@
-workflow:
-  rules: 
-    - if: '$CI_PIPELINE_SOURCE == "merge_request_event" && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "main"'
-
-default:
-  image: 'quirinecker/rust-openssl'
-
-build:
-  script:
-    - cargo build
-
-test: 
-  script:
-    - cargo test
-
-# publish:
-#   script:
-#     - export CARGO_REGISTRY_TOKEN=$CARGO_TOKEN
-#     - cargo publish
-