Bump lower constraints for OSC

In support of the OSC migration, we need
to bump the lower-constraint for the
openstacksdk to allow for feature parity.

Change-Id: Ide69f84a76f06814cf74b73b57729f23dea1062b

lower-constraints.txt

@@ -60,7 +60,7 @@ munch==2.2.0
 netaddr==0.7.18
 netifaces==0.10.6
 neutron-lib==1.14.0
-openstacksdk==0.11.2
+openstacksdk==0.28.0
 os-client-config==1.29.0
 os-service-types==1.2.0
 osc-lib==1.10.0

requirements.txt

@@ -14,7 +14,7 @@ keystonemiddleware>=5.1.0 # Apache-2.0
 lxml!=3.7.0,>=4.5.0 # BSD
 netaddr>=0.7.18 # BSD
 neutron-lib>=1.14.0  # Apache-2.0
-openstacksdk>=0.11.2 # Apache-2.0
+openstacksdk>=0.28.0 # Apache-2.0
 oslo.cache>=1.26.0 # Apache-2.0
 oslo.config>=6.8.0 # Apache-2.0
 oslo.concurrency>=3.26.0 # Apache-2.0