Speed up execution of thermalctld unit tests

sonic-thermalctld/tests/mock_swsscommon.py

@@ -27,6 +27,9 @@ def get(self, key):
     def get_size(self):
         return (len(self.mock_dict))
 
+    def getKeys(self):
+        return list(self.mock_dict.keys())
+
 
 class FieldValuePairs:
     def __init__(self, fvs):

sonic-thermalctld/tests/mocked_libs/swsscommon/swsscommon.py

@@ -2,10 +2,32 @@
     Mock implementation of swsscommon package for unit testing
 '''
 
-from swsssdk import ConfigDBConnector, SonicDBConfig, SonicV2Connector
-
 STATE_DB = ''
 
+class ConfigDBConnector:
+    """
+    Mock ConfigDBConnector that avoids real Redis connections.
+    """
+    def __init__(self, *args, **kwargs):
+        pass
+
+    def connect(self, *args, **kwargs):
+        pass
+
+    def get_table(self, table_name):
+        return {}
+
+    def get_entry(self, table, key):
+        return {}
+
+
+class SonicV2Connector:
+    def __init__(self, *args, **kwargs):
+        pass
+
+    def connect(self, *args, **kwargs):
+        pass
+
 
 class Table:
     def __init__(self, db, table_name):