Revert "ci: install python3-pyparsing in the ubuntu2004 image"
Revert "ci: install python3-pyparsing in the ubuntu2004 image"

This reverts commit 2a4bfcc35fe362df97768ed533e8ebd0474f4f23.

h2o/h2o,yannick/h2o,devnexen/h2o,h2o/h2o,devnexen/h2o,h2o/h2o,devnexen/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,h2o/h2o,yannick/h2o,h2o/h2o,cwyang/h2o,h2o/h2o,yannick/h2o,devnexen/h2o,devnexen/h2o,h2o/h2o,h2o/h2o,devnexen/h2o,devnexen/h2o,yannick/h2o,yannick/h2o,yannick/h2o,yannick/h2o,devnexen/h2o,yannick/h2o,devnexen/h2o,h2o/h2o,yannick/h2o