Remove obsolete schema

Author: Mats-SX

doc/modules/ROOT/pages/gds-session.adoc

@@ -212,8 +212,6 @@ With the `gds` GDS Session active, project the graph and specify node and relati
 .Project a graph into the GDS Session:
 [source,python,role=no-test]
 ----
-from graphdatascience.session import GdsPropertyTypes
-
 G, result = gds.graph.project(
     graph_name="my-graph",
     query="""

graphdatascience/session/__init__.py

@@ -1,7 +1,6 @@
 from .algorithm_category import AlgorithmCategory
 from .dbms_connection_info import DbmsConnectionInfo
 from .gds_sessions import AuraAPICredentials, GdsSessions
-from .schema import GdsPropertyTypes
 from .session_info import SessionInfo
 from .session_sizes import SessionMemory
 
@@ -11,6 +10,5 @@
     "DbmsConnectionInfo",
     "AuraAPICredentials",
     "SessionMemory",
-    "GdsPropertyTypes",
     "AlgorithmCategory",
 ]