ci: Port pipelinelib to gitlab-ci

Bug: T344744

.gitlab-ci.yml

@@ -0,0 +1,19 @@
+stages:
+  - test
+
+variables:
+  CARGO_BUILD_JOBS: "1"
+  IRCSERVSERV_REPO: "https://gerrit.wikimedia.org/r/wikimedia/irc/ircservserv"
+  IRCSERVSERV_REV: "f5f4d95"
+
+test-validate:
+  stage: test
+  tags:
+    - wmcs
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
+  image: rust:latest
+  script:
+    - cargo install --locked --git $IRCSERVSERV_REPO --rev $IRCSERVSERV_REV
+    - /usr/local/cargo/bin/validate-config channels

.pipeline/blubber.yaml

@@ -1,27 +0,0 @@
-version: v4
-base: docker-registry.wikimedia.org/wikimedia-buster:latest
-variants:
-  build:
-    base: docker-registry.wikimedia.org/releng/rust:1.56.1-1
-  prep:
-    includes: [build]
-    builder:
-      command:
-        - cargo
-        - install
-        - "--locked"
-        - "--git"
-        - "https://gerrit.wikimedia.org/r/wikimedia/irc/ircservserv"
-        - "--rev"
-        - f5f4d95
-  validate:
-    copies:
-      - from: prep
-        source: /usr/local/cargo/bin/validate-config
-        destination: /usr/local/bin/validate-config
-      - from: local
-        source: .
-        destination: .
-    entrypoint:
-      - "/usr/local/bin/validate-config"
-      - "channels"

.pipeline/config.yaml

@@ -1,7 +0,0 @@
-pipelines:
-  test:
-    blubberfile: blubber.yaml
-    stages:
-      - name: validate
-        build: validate
-        run: true