Fix: Stopping executions could be returned

Calling `get_running_vm(...)` could return an execution that is in a stopping state, causing issues in the next steps of the process.

src/aleph/vm/models.py

@@ -90,6 +90,10 @@ def is_running(self):
             else self.systemd_manager.is_service_active(self.controller_service)
         )
 
+    @property
+    def is_stopping(self) -> bool:
+        return bool(self.times.stopping_at and not self.times.stopped_at)
+
     @property
     def is_program(self):
         return isinstance(self.message, ProgramContent)

src/aleph/vm/pool.py

@@ -164,7 +164,7 @@ def get_unique_vm_id(self) -> int:
     async def get_running_vm(self, vm_hash: ItemHash) -> Optional[VmExecution]:
         """Return a running VM or None. Disables the VM expiration task."""
         execution = self.executions.get(vm_hash)
-        if execution and execution.is_running:
+        if execution and execution.is_running and not execution.is_stopping:
             execution.cancel_expiration()
             return execution
         else: