db: Drop support for experimental concurrency

The 'oslo_db.concurrency.TpoolDbapiWrapper' wrapper was deprecated in
oslo.db 11.0.0 release[1]. This follows the changes done by the other
projects like nova[2].

[1] 74c6bf266e0b86ceb4726cad9268f134d423bae8
[2] 9799468d6f31ba8d915c851aae1a66340b5d1d7f

Change-Id: I4381ee84eaa0e7623210727f6da9278e8c080af1

masakari/db/api.py

@@ -19,15 +19,15 @@ Call these functions from masakari.db namespace, not the masakari.db.api
 namespace.
 """
 
-from oslo_db import concurrency
+from oslo_db import api
 
 import masakari.conf
 
 CONF = masakari.conf.CONF
 
-_BACKEND_MAPPING = {'sqlalchemy': 'masakari.db.sqlalchemy.api'}
-
-IMPL = concurrency.TpoolDbapiWrapper(CONF, backend_mapping=_BACKEND_MAPPING)
+IMPL = api.DBAPI.from_config(
+    conf=CONF, backend_mapping={'sqlalchemy': 'nova.db.sqlalchemy.api'},
+)
 
 # The maximum value a signed INT type may have
 MAX_INT = 0x7FFFFFFF

releasenotes/notes/drop-oslo_db-use_tpool-fb7134d9f9cad80f.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    Experimental support for thread pooling of DB API calls has been removed.