Remove Oracle storage implementation

env.example

@@ -109,16 +109,6 @@ LIGHTRAG_VECTOR_STORAGE=NanoVectorDBStorage
 LIGHTRAG_GRAPH_STORAGE=NetworkXStorage
 LIGHTRAG_DOC_STATUS_STORAGE=JsonDocStatusStorage
 
-### Oracle Database Configuration
-ORACLE_DSN=localhost:1521/XEPDB1
-ORACLE_USER=your_username
-ORACLE_PASSWORD='your_password'
-ORACLE_CONFIG_DIR=/path/to/oracle/config
-#ORACLE_WALLET_LOCATION=/path/to/wallet
-#ORACLE_WALLET_PASSWORD='your_password'
-### separating all data from difference Lightrag instances(deprecating)
-#ORACLE_WORKSPACE=default
-
 ### TiDB Configuration
 TIDB_HOST=localhost
 TIDB_PORT=4000