Add caching of pip, hatch and hatch envs in doc-tests workflow and de-duplicate the env setup

[martinhoyer]

• Adding pip cache for docs test and release actions. pre-commit action has it's own cache and in testing, there was no benefit in adding pip cache at all.

• Consolidating the html and linkcheck jobs to a single one to only run one checkout, python-setup(incl. cache) and pip install hatch.

• Adding cache action for hatch environments for docs-test.