Fix: Abnormal strings appear when comments are saved after editing (#29991)
Partially resolved(The second problem):
[#29986](https://github.com/go-gitea/gitea/issues/29986)
**Before**
HTML strings appear when comments are saved after editing

**After**
https://github.com/go-gitea/gitea/assets/37935145/525601f9-3ee1-4266-9105-36d82b91b1c8
(cherry picked from commit bf34723491dcbb45dee7888c574e295cae6096be)
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