Update nbconvert to 6.4.x, add optional package pyppeteer

[mkoeppe]

The update to 6.4.x (https://nbconvert.readthedocs.io/en/latest/changelog.html) brings some improvements to webpdf exports.

6.4.x (and main as of 2022-03) still supports python 3.7, as needed for Sage 9.6

There is a new dependency, beautifulsoup4. We convert the existing pip package to a standard normal package.

• https://github.com/jupyter/nbconvert/blob/main/setup.py#L214

The new package Pyppeteer is needed for webpdf exports of Jupyter notebooks.

pyppeteer has a number of new dependencies, so for now we only add it as a pip package.

• https://github.com/pyppeteer/pyppeteer/blob/dev/pyproject.toml#L46

CC: @kwankyu

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: 6219340

Reviewer: Kwankyu Lee

Issue created by migration from https://trac.sagemath.org/ticket/33533

[mkoeppe]

Branch: u/mkoeppe/update_nbconvert_to_6_4_x__add_optional_package_pyppeteer

[sagetrac-git]

Commit: 652d823

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

652d823

build/pkgs/pyppeteer: New pip package

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1,11 +1,13 @@
-[Pyppeteer](https://github.com/pyppeteer/pyppeteer) is needed for [webpdf exports](https://nbconvert.readthedocs.io/en/latest/usage.html#webpdf) of the Jupyter notebook.
-
 The update to 6.4.x (https://nbconvert.readthedocs.io/en/latest/changelog.html) brings some improvements to webpdf exports.
 
 6.4.x (and main as of 2022-03) still supports python 3.7, as needed for Sage 9.6
 
-https://github.com/jupyter/nbconvert/blob/main/setup.py#L214
+There is a new dependency, `beautifulsoup4`. We convert the existing pip package to a standard normal package.
+- https://github.com/jupyter/nbconvert/blob/main/setup.py#L214
 
-pyppeteer has a number of new dependencies, so for now we should only add it as a pip package.
-https://github.com/pyppeteer/pyppeteer/blob/dev/pyproject.toml#L46
 
+The new package [Pyppeteer](https://github.com/pyppeteer/pyppeteer) is needed for [webpdf exports](https://nbconvert.readthedocs.io/en/latest/usage.html#webpdf) of Jupyter notebooks.
+
+pyppeteer has a number of new dependencies, so for now we only add it as a pip package.
+- https://github.com/pyppeteer/pyppeteer/blob/dev/pyproject.toml#L46
+

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

2c8fd61

configure.ac (--disable-notebook): Also disable beautifulsoup4

[sagetrac-git]

Changed commit from 652d823 to 2c8fd61

[kwankyu]

comment:6

We convert the existing pip package to a standard normal package.

Then we need a discussion on sage-devel?

[mkoeppe]

comment:7

No, we have routinely added new dependencies of standard packages as standard packages on upgrades in the past

[kwankyu]

comment:8

LGTM.

[kwankyu]

Reviewer: Kwankyu Lee

[mkoeppe]

comment:9

Thanks!

[vbraun]

comment:10

sage -t --long --warn-long 48.1 --random-seed=123 src/sage/misc/package.py
**********************************************************************
File "src/sage/misc/package.py", line 564, in sage.misc.package.optional_packages
Failed example:
    'beautifulsoup4' in installed+not_installed  # optional - sage_spkg
Expected:
    True
Got:
    False
**********************************************************************
1 item had failures:
   1 of   4 in sage.misc.package.optional_packages
    [56 tests, 1 failure, 3.67 s]
----------------------------------------------------------------------
sage -t --long --warn-long 48.1 --random-seed=123 src/sage/misc/package.py  # 1 doctest failed
----------------------------------------------------------------------