enable fossa scanning (#2895)

* enable fossa scanning 

request: https://github.com/rancherlabs/eio/issues/772

* fossa should not fail CI

Co-authored-by: Ross Kirkpatrick <ross.kirkpatrick@suse.com>

.drone.yml

@@ -175,3 +175,18 @@ volumes:
 - name: socket
   host:
     path: /var/run/docker.sock
+
+---
+kind: pipeline
+name: fossa
+
+steps:
+- name: fossa
+  image: rancher/drone-fossa:latest
+  failure: ignore
+  settings:
+    api_key:
+      from_secret: FOSSA_API_KEY
+    when:
+      instance:
+        - drone-publish.rancher.io