attempt 2

Signed-off-by: Christian Richter <crichter@owncloud.com>

.drone.star

@@ -1,9 +1,34 @@
 def main(ctx):
   return [
+    cancelPreviousBuilds(),
     step("amd64"),
     step("arm64"),
   ]
 
+def cancelPreviousBuilds():
+  return [{
+      "kind": "pipeline",
+        "type": "docker",
+        "name": "cancel-previous-builds",
+        "clone": {
+            "disable": True,
+        },
+        "steps": [{
+            "name": "cancel-previous-builds",
+            "image": "owncloudci/drone-cancel-previous-builds",
+            "settings": {
+                "DRONE_TOKEN": {
+                    "from_secret": "drone_token",
+                },
+            },
+        }],
+        "trigger": {
+            "ref": [
+                "refs/pull/**",
+            ],
+        },
+    }]
+
 def step(arch):
   return {
     "kind": "pipeline",