mypy CI Caching leading to complications

[miketheman]

A weird failure surfaced during the Lint step in CI:

Run 1: https://github.com/pypi/warehouse/actions/runs/5358896351/jobs/9721824117?pr=14012
Run 2: https://github.com/pypi/warehouse/actions/runs/5358896351/jobs/9721955335#step:7:87

Deleting the Cache and rerunning all jobs succeeded.

Turns out that we made our own cache collision by reusing the same key for the python env and the mypy cache results.

These two are the same cache and should be the same:

warehouse/.github/workflows/ci.yml

Line 37 in 8d01d4b

key: ${{ runner.os }}-${{ env.pythonLocation }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}

warehouse/.github/workflows/ci.yml

Line 101 in 8d01d4b

key: ${{ runner.os }}-${{ env.pythonLocation }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}

The mypy cache should probably have a unique identifier tacked on to the end:

warehouse/.github/workflows/ci.yml

Lines 95 to 96 in 8d01d4b

	.mypy_cache
	key: ${{ runner.os }}-${{ env.pythonLocation }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}