[enhance](Nereids): delete output in olapscan toString()

[jackwener]

Proposed changes

Issue Number: close #xxx

Problem summary

delete output in olapscan toString()

Checklist(Required)

• [x] Does it affect the original behavior
• [ ] Has unit tests been added
• [ ] Has document been added or modified
• [ ] Does it need to update dependencies
• [x] Is this PR support rollback (If NO, please explain WHY)

Further comments

If this is a relatively large or complex change, kick off the discussion at [email protected] by explaining why you chose the solution you did and what alternatives you considered, etc...

[jackwener]

run buildall

[jackwener]

run buildall

[github-actions[bot]]

PR approved by at least one committer and no changes requested.

[github-actions[bot]]

PR approved by anyone and no changes requested.