closes #128.

* 🔧 MAINTAIN: Remove manual pre-commit from CI

* Remove dependency on pre-commit in publish Action

* [pre-commit.ci] pre-commit autoupdate

updates:
- git://github.com/pre-commit/pre-commit-hooks: v2.2.3 → v4.0.1
- [github.com/mgedmin/check-manifest: 0.39 → 0.46](mgedmin/check-manifest@0.39...0.46)
- [github.com/psf/black: stable → 21.7b0](psf/black@stable...21.7b0)
- [github.com/PyCQA/pylint: pylint-2.4.2 → v2.9.5](pylint-dev/pylint@pylint-2.4.2...v2.9.5)

* Change exception raising to use 'from' syntax

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Bump pre-commit version

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: foster999 <foster.dev999@gmail.com>

…sets (#132)

* 👌 IMPROVE: Use Sphinx HTML assets policy to decide whether include assets

Sphinx v4.1.0 will include `Sphinx.registry.html_assets_policy` that defines the
policy to whether include or not HTML assets in pages where the extension is not
used.

This PR makes usage of this policy to decide if sphinx-tabs assets should be
included or not in the page that's being rendered.

Reference: sphinx-doc/sphinx#9115

* Update test for conditional assets

* Run pre-commit

Co-authored-by: Manuel Kaufmann <humitos@gmail.com>

Make the test work with Sphinx 4.0.x.
Fix the typo so that the regression file is actually found.

* Include testing for python 3.9

* Remove pygments output from regression test HTML

* Add pygments version paramtrization to Actions CI

* Change CI sphinx version from pre-release

* Add new regression outputs for Sphinx 4

* Change test to use independent root

* [pre-commit.ci] pre-commit autoupdate

updates:
- git://github.com/pre-commit/pre-commit-hooks: v4.0.1 → v4.1.0
- [github.com/mgedmin/check-manifest: 0.46 → 0.47](mgedmin/check-manifest@0.46...0.47)
- [github.com/psf/black: 21.7b0 → 22.1.0](psf/black@21.7b0...22.1.0)
- [github.com/PyCQA/pylint: v2.9.5 → v2.12.2](pylint-dev/pylint@v2.9.5...v2.12.2)

* Update .pre-commit-config.yaml to trigger Actions

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: David Foster <31405412+foster999@users.noreply.github.com>