Update pip related commands for docker (#31106)

Thanks to graelo and silverwind for figuring out the problem.

Fix #31101

Author: wxiaoguang

docs/content/administration/external-renderers.en-us.md

@@ -38,12 +38,10 @@ FROM gitea/gitea:@version@
 COPY custom/app.ini /data/gitea/conf/app.ini
 [...]
 
-RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng libffi-dev py-pip python3-dev py3-pip py3-pyzmq
+RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng libffi-dev pandoc python3-dev py3-pyzmq pipx
 # install any other package you need for your external renderers
 
-RUN pip3 install --upgrade pip
-RUN pip3 install -U setuptools
-RUN pip3 install jupyter docutils
+RUN pipx install jupyter docutils --include-deps
 # add above any other python package you may need to install
 ```
 

docs/content/administration/external-renderers.zh-cn.md

@@ -37,12 +37,10 @@ FROM gitea/gitea:@version@
 COPY custom/app.ini /data/gitea/conf/app.ini
 [...]
 
-RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng libffi-dev py-pip python3-dev py3-pip py3-pyzmq
+RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng libffi-dev pandoc python3-dev py3-pyzmq pipx
 # 安装其他您需要的外部渲染器的软件包
 
-RUN pip3 install --upgrade pip
-RUN pip3 install -U setuptools
-RUN pip3 install jupyter docutils
+RUN pipx install jupyter docutils --include-deps
 # 在上面添加您需要安装的任何其他 Python 软件包
 ```