Remove rustfmt check from gitlab-ci.yml

All files are autogenerated and don't conform to what rustfmt would do

.gitlab-ci.yml

@@ -1,6 +1,5 @@
 stages:
   - "test"
-  - "lint"
 
 .cargo_cache: &cache
   cache:
@@ -66,11 +65,3 @@ test nightly:
   image: "rustlang/rust:nightly-slim"
   allow_failure: true
   <<: *cargo_test
-
-rustfmt:
-  image: "rustlang/rust:nightly-slim"
-  stage: "lint"
-  script:
-    - rustup component add rustfmt-preview
-    - cargo fmt --version
-    - cargo fmt -- --color=always --check