chore: remove redundant tag in old scenarios

[XianBW]

Description

rdagent/log/ui/app.py can show log trace with new tag system or old tag system (r, d, ef).

Motivation and Context

How Has This Been Tested?

• [ ] If you are adding a new feature, test on your own test scripts.

Screenshots of Test Results (if appropriate):

1. Your own tests:

Types of changes

• [ ] Fix bugs
• [ ] Add new feature
• [ ] Update documentation

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📚 Documentation preview 📚: https://RDAgent--917.org.readthedocs.build/en/917/