[MOSIP-44613] add signup namespace to esignet testrigs DSF namespaces section

esignet-signup-apitestrig deploys into the signup namespace but it was
missing from the namespaces: block, causing Helmsman validation to fail.

Signed-off-by: bhumi46 <bhumi11111a@gmail.com>
Signed-off-by: bhumi46 <thisisbn46@gmail.com>

Author: bhumi46

Helmsman/dsf/esignet/testrigs-dsf.yaml

@@ -23,6 +23,8 @@ namespaces:
     protected: false
   esignet-sunbird:
     protected: false
+  signup:
+    protected: false
   signup-uitestrig:
     protected: false