add_forge_now/models: Add missing transitions between request statuses

Related to #4779.

swh/web/add_forge_now/models.py

@@ -56,7 +56,7 @@ class RequestStatus(enum.Enum):
                 cls.SUSPENDED,
                 cls.UNSUCCESSFUL,
             ],
-            cls.ACCEPTED: [cls.SCHEDULED],
+            cls.ACCEPTED: [cls.SCHEDULED, cls.REJECTED, cls.UNSUCCESSFUL],
             cls.SCHEDULED: [
                 cls.FIRST_LISTING_DONE,
                 # in case of race condition between lister and loader:
@@ -66,7 +66,7 @@ class RequestStatus(enum.Enum):
             cls.FIRST_ORIGIN_LOADED: [],
             cls.REJECTED: [],
             cls.SUSPENDED: [cls.PENDING],
-            cls.UNSUCCESSFUL: [],
+            cls.UNSUCCESSFUL: [cls.ACCEPTED],
         }
 
     @classmethod

swh/web/add_forge_now/tests/test_models.py

@@ -39,6 +39,18 @@ from swh.web.add_forge_now.models import Request, RequestStatus
                 RequestStatus.UNSUCCESSFUL,
             ],
         ),
+        (
+            RequestStatus.ACCEPTED,
+            [
+                RequestStatus.SCHEDULED,
+                RequestStatus.REJECTED,
+                RequestStatus.UNSUCCESSFUL,
+            ],
+        ),
+        (
+            RequestStatus.UNSUCCESSFUL,
+            [RequestStatus.ACCEPTED],
+        ),
     ],
 )
 def test_allowed_next_statuses(current_status, allowed_next_statuses):