Try yaml anchors

.drone.yml

@@ -7,19 +7,22 @@ name: Build the builder
 trigger:
   event:
     - push
-environment:
-  BUILDER_VERSION: 555262114ea81f6f286010474527f419b56d33a3
+
+image-anchor: &image-anchor
+  image: git.badhouseplants.net/badhouseplants/badhouseplants-builder:555262114ea81f6f286010474527f419b56d33a3
+
 steps:
-  - name: Build and push the docker image
-    image: git.badhouseplants.net/badhouseplants/badhouseplants-builder:${BUILDER_VERSION}
+  - <<: *image-anchor
+    name: Build and push the docker image
     privileged: true
     environment:
       GITEA_TOKEN:
         from_secret: GITEA_TOKEN
     commands:
       - build-container
-  - name: Cleanup registry
-    image: git.badhouseplants.net/badhouseplants/badhouseplants-builder:${BUILDER_VERSION}
+
+  - <<: *image-anchor
+    name: Cleanup registry
     environment:
       GITEA_TOKEN:
         from_secret: GITEA_TOKEN