chore(helm): bump pipeline-backend db version (#1082)

Because

- Integration feature modifies the pipeline database.

This commit

- bump pipeline-backend db version

charts/core/values.yaml

@@ -388,7 +388,7 @@ pipelineBackend:
   # -- The path of configuration file for pipeline-backend
   configPath: /pipeline-backend/config/config.yaml
   # -- The database migration version
-  dbVersion: 24
+  dbVersion: 26
   # -- workflow setting
   workflow:
     maxWorkflowTimeout: 3600 # in seconds