Added workflow call to tests.yml

Signed-off-by: Ole Herman Schumacher Elgesem <ole.elgesem@northern.tech>

Author: olehermanse

.github/workflows/tests.yml

@@ -8,6 +8,7 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+  workflow_call:
 
 permissions:
   contents: read