Remove pytest cache clearing #683

	name: Build Thetis

	on:
	# Push to master or PR
	push:
	branches:
	- master
	pull_request:
	schedule:
	# * is a special character in YAML so you have to quote this string
	# Scheduled build at 0230 UTC on Monday mornings to detect bitrot.
	- cron: '30 2 * * 1'

	jobs:
	build:
	name: "Build Thetis"
	# The type of runner that the job will run on
	runs-on: self-hosted
	# The docker container to use.
	container:
	image: firedrakeproject/firedrake-vanilla:latest
	steps:
	- uses: actions/checkout@v2
	- name: Cleanup
	if: ${{ always() }}
	run: \|
	cd ..
	rm -rf build
	- name: Install Thetis
	run: \|
	. /home/firedrake/firedrake/bin/activate
	python -m pip install -r requirements.txt
	python -m pip install -e .
	- name: Test Thetis
	run: \|
	. /home/firedrake/firedrake/bin/activate
	python $(which firedrake-clean)
	python -m pytest -n 12 -v test
	- name: Test Thetis adjoint
	run: \|
	. /home/firedrake/firedrake/bin/activate
	python $(which firedrake-clean)
	python -m pytest -n 12 -v test_adjoint
	- name: Lint
	if: ${{ always() }}
	run: \|
	. /home/firedrake/firedrake/bin/activate
	make lint

Provide feedback