Close#28287
## How to test it in local
convert Makefile L34 into:
```
cd .tmp/upstream-docs && git clean -f && git reset --hard && git fetch origin pull/28302/head:pr28302 && git switch pr28302
```
https://gitea.com/gitea/gitea-docusaurus/actions/runs/661/jobs/0#jobstep-9-39
I noticed that there are many warning logs in building docs.
It is causing 404 in docs.gitea.com now, so we need to fix it.
And there are also some other problems in v1.19 which can not be done in
this PR.
ps: Are there any good methods to test this in local?
yp05327