Add test for invalid job types in workflow's job_outputs

plugins/lua/workflow.lua

@@ -355,4 +355,10 @@ function listWeakenedConstraints(outputs)
     return variants
 end
 
+if dfhack.internal.IN_TEST then
+    test_data = {
+        job_outputs = job_outputs,
+    }
+end
+
 return _ENV

test/plugins/workflow.lua

@@ -0,0 +1,7 @@
+local workflow = require('plugins.workflow')
+
+function test.job_outputs()
+    for job_type in pairs(workflow.test_data.job_outputs) do
+        expect.true_(df.job_type[job_type], "Found unrecognized job type: " .. tostring(job_type))
+    end
+end