see if python 3.9 fixes the copybutton

# Required

version: 2

build:

  os: ubuntu-20.04

  tools:

    python: "3.9"

    nodejs: 16

# Build documentation in the docs/ directory with Sphinx

sphinx:

  builder: html

  fail_on_warning: true

# Optionally build your docs in additional formats such as PDF

formats:

  - pdf

formats: all

# Optionally set the version of Python and requirements required to build your docs

python:

  version: 3.8

  install:

    - requirements: doc/requirements.txt

    - method: pip