Upgrade Sphinx, myst-parser and docutils

[jpmckinney]

• Sphinx
  • standard_profile_template is pinned to 5.3.0 https://www.sphinx-doc.org/en/master/changes.html
  • extension-explorer is 7.2.5 (recent)
  • Changes
    • Removes jQuery and underscore.js
• docutils
  • standard_profile_template is pinned to 0.18 https://www.docutils.org/RELEASE-NOTES.html
  • extension-explorer is 0.20.1 (recent)
  • No notable changes
• myst-parser
  • standard_profile_template is pinned to 0.18.1 https://myst-parser.readthedocs.io/en/latest/develop/_changelog.html
  • extension-explorer is 2.0.0 (recent)
  • Changes
    • Even more Markdown link options
    • Attributes syntax, e.g. for code highlighting (just use Sphinx directive instead). I checked and we don't have any HTML in .rst or .md where we could use this syntax (we use HTML for small, style, script, iframe, etc.).
    • Duplicate label in translation only executablebooks/MyST-Parser#357 might now be fixed by 👌 Handling of nested headers executablebooks/MyST-Parser#711. Affects standard/docs/conf.py
    • Updates markdown-it-py, mdit-py-plugins, linkify-it-py, but unlikely to change anything on our end

ocds-extensions-translations seems able to use the latest versions; it was last updated to Sphinx 8.0.2 (8.2.3 is latest), docutils 0.21.2 (latest) and myst-parser 4.0.0 (4.0.1 is latest).

Based on last time #71, we might need to:

• Add jQuery to standard_theme https://www.sphinx-doc.org/en/master/changes.html#id197
• Test if can remove comment suppress_warnings in standard/docs/conf.py
• Check that Sphinx extensions still work, especially if ours or ODS' (run pytest tests with latest versions)
• Test JavaScript behaviors:
  • standard script.js
  • infrastructure json-example-format.js (same as last part of standard script.js)
  • standard_theme theme.js search.js
  • public-private-partnerships show-shower.js
• Test ocds-index with latest versions

Last time we had to update some non-documentation projects (e.g. removing :widths: auto last time), but docutils has very limited HTML changes, this time.

Noting that this bug still exists:

Would need to update translation logic in standard_theme, but Sphinx has a bug anyway sphinx-doc/sphinx#11008