🔧 chore(render.yaml): add LANGFLOW_DATABASE_URL environment variable with sqlite database path to improve configuration

The LANGFLOW_DATABASE_URL environment variable is added with the value `sqlite:////home/user/.cache/langflow/langflow.db` to specify the path to the SQLite database file for the Langflow service. This improves the configuration by providing a specific location for the database file.

render.yaml

@@ -8,6 +8,9 @@ services:
     branch: main
     healthCheckPath: /health
     autoDeploy: false
+    envVars:
+      - key: LANGFLOW_DATABASE_URL
+      - value: sqlite:////home/user/.cache/langflow/langflow.db
     disk:
       name: langflow-data
       mountPath: /home/user/.cache/langflow