Actually build repo in CI

.woodpecker/test-workflow.yml

@@ -3,11 +3,6 @@ when:
     branch: master
 
 steps:
-  - name: build
-    image: alpine
-    commands:
-      - echo "Hello world"
-
   - name: docker-build
     image: woodpeckerci/plugin-kaniko
     settings:
@@ -23,5 +18,10 @@ steps:
         branch: master
       - event: pull_request
 
+  - name: build
+    image: fedichat/rust_builder
+    commands:
+      - cargo build
+