The value of 10 does not really fit some of our world patterns and values
up to 15 may be acceptable. Looking at some worlds, 14 seems to be
achievable without too much work and reduces the noise in test output,
making it more usable.
* CI: add a workflow to show flake8 violations in modified files of a PR
* modify a file to trigger the lint check
* CI: add a workflow to show mypy violations in modified files of a PR
* modify a file to trigger the type check
* Split flake8 and mypy into two parallel jobs; run a variant of the workflow on push event; modify a file to trigger the push workflow
* fail the task if there are syntax errors; remove old lint workflow
