Don't mistakenly take a lock on DagRun via ti.refresh_from_fb

In 2.2.0 we made TI.dag_run be automatically join-loaded, which is fine
for most cases, but for `refresh_from_db` we don't need that (we don't
access anything under ti.dag_run) and it's possible that when
`lock_for_update=True` is passed we are locking more than we want to and
_might_ cause deadlocks.

Even if it doesn't, selecting more than we need is wasteful.

airflow/models/taskinstance.py

@@ -848,28 +848,32 @@ def refresh_from_db(self, session: Session = NEW_SESSION, lock_for_update: bool
         """
         self.log.debug("Refreshing TaskInstance %s from DB", self)
 
-        qry = session.query(TaskInstance).filter(
-            TaskInstance.dag_id == self.dag_id,
-            TaskInstance.task_id == self.task_id,
-            TaskInstance.run_id == self.run_id,
-            TaskInstance.map_index == self.map_index,
+        qry = (
+            # To avoid joining any relationships by default select the all
+            # columns, not the object. This also means we get (effectively) a
+            # namedtuple back, not a TI object
+            session.query(*TaskInstance.__table__.columns).filter(
+                TaskInstance.dag_id == self.dag_id,
+                TaskInstance.task_id == self.task_id,
+                TaskInstance.run_id == self.run_id,
+                TaskInstance.map_index == self.map_index,
+            )
         )
 
         if lock_for_update:
             for attempt in run_with_db_retries(logger=self.log):
                 with attempt:
-                    ti: Optional[TaskInstance] = qry.with_for_update().first()
+                    ti: Optional[TaskInstance] = qry.with_for_update().one_or_none()
         else:
-            ti = qry.first()
+            ti = qry.one_or_none()
         if ti:
             # Fields ordered per model definition
             self.start_date = ti.start_date
             self.end_date = ti.end_date
             self.duration = ti.duration
             self.state = ti.state
-            # Get the raw value of try_number column, don't read through the
-            # accessor here otherwise it will be incremented by one already.
-            self.try_number = ti._try_number
+            # Since we selected columns, not the object, this is the raw value
+            self.try_number = ti.try_number
             self.max_tries = ti.max_tries
             self.hostname = ti.hostname
             self.unixname = ti.unixname