Rollup merge of #44086 - kennytm:htmldocck-python3, r=Mark-Simulacrum
Rollup merge of #44086 - kennytm:htmldocck-python3, r=Mark-Simulacrum

Allow `htmldocck.py` to run using Python 3

GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust