Remove deprecated cifmw_tempest_tempestconf_config

The cifmw_tempest_tempestconf_config has been deprecated for a
while, so it would be the best to start using the new alternative
cifmw_test_operator_tempest_tempestconf_config. There should be no
impact on the jobs, it should just let us cleanup the deprecated
parameter.

Author: kstrenkova

ci/tests/watcher-tempest.yml

@@ -1,5 +1,5 @@
 # # Tempest and test-operator configurations
-cifmw_tempest_tempestconf_config:
+cifmw_test_operator_tempest_tempestconf_config:
   overrides: |
     compute.min_microversion 2.56
     compute.min_compute_nodes 2