Add caching to deps

[kjaymiller]

blackpythondevs.github.io/.github/workflows/playwright.yml

Lines 24 to 28 in af46ba5

	- name: Install dependencies
	run: |
	python -m pip install --upgrade pip
	pip install -r requirements-dev.txt
	python -m playwright install --with-deps chromium

Currently we have to reinstall all of the tools over and over again. With Playwright, this a little expensive resource-wise.

We can add caching to our pip installs to speed up the process some and reduce processing time.

FMI - https://github.com/actions/setup-python#caching-packages-dependencies

[kjaymiller]

Fixed in #642 - Due to needing to specify versions.