Make MAPPED_SCYLLA_VERSION a soft requirement

It is going to ease development and test process.
From now on if you want to run it on release you can just run it as
such:
SCYLLA_VERSION="6.0.2" pytest ....

ci/run_integration_test.sh

@@ -36,6 +36,5 @@ ccm remove
 
 # run test
 
-export MAPPED_SCYLLA_VERSION=3.11.4
 PROTOCOL_VERSION=4  pytest -rf --import-mode append $*
 

tests/integration/__init__.py

@@ -180,15 +180,16 @@ def _get_dse_version_from_cass(cass_version):
 # Supported Clusters: Cassandra, DDAC, DSE, Scylla
 DSE_VERSION = None
 SCYLLA_VERSION = os.getenv('SCYLLA_VERSION', None)
+SCYLLA_SOURCE = SCYLLA_VERSION
 if os.getenv('DSE_VERSION', None):  # we are testing against DSE
     DSE_VERSION = Version(os.getenv('DSE_VERSION', None))
     DSE_CRED = os.getenv('DSE_CREDS', None)
     CASSANDRA_VERSION = _get_cass_version_from_dse(DSE_VERSION.base_version)
     CCM_VERSION = DSE_VERSION.base_version
-else:  # we are testing against Cassandra or DDAC
+else:  # we are testing against Cassandra,DDAC or Scylla
     if SCYLLA_VERSION:
         cv_string = SCYLLA_VERSION
-        mcv_string = os.getenv('MAPPED_SCYLLA_VERSION', None)
+        mcv_string = os.getenv('MAPPED_SCYLLA_VERSION', '3.11.4') # Assume that scylla matches cassandra `3.11.4` behavior
     else:
         cv_string = os.getenv('CASSANDRA_VERSION', None)
         mcv_string = os.getenv('MAPPED_CASSANDRA_VERSION', None)
@@ -201,6 +202,9 @@ def _get_dse_version_from_cass(cass_version):
     CASSANDRA_VERSION = Version(mcv_string) if mcv_string else cassandra_version
     CCM_VERSION = mcv_string if mcv_string else cv_string
 
+    CASSANDRA_VERSION = Version(mcv_string) if mcv_string else cassandra_version
+    CCM_VERSION = mcv_string if mcv_string else cv_string
+
 CASSANDRA_IP = os.getenv('CLUSTER_IP', '127.0.0.1')
 CASSANDRA_DIR = os.getenv('CASSANDRA_DIR', None)