Since pytest-bdd v8.0.0 uses the official Gherkin parser, multiline
strings must now be encapsulated by triple-quotes.

See:
- https://pytest-bdd.readthedocs.io/en/stable/#id2
- https://pytest-bdd.readthedocs.io/en/stable/#docstrings

These comments break the step matching.

In pytest-bdd v8.0.0 it is no longer possible to match based on multiple
lines, which breaks essentially all steps that support docstrings. Solve
this by adding a wrapper-function for each of these instances, that
matches the docstring step, and calls the original function.

So, what used to be:

    @then(parse("the output should match\n{regex}"))
    @then(parse('the output should match "{regex}"'))
    def output_should_match(regex, cli_run):
        ...

Is now:

    @then(parse("the output should match"))
    def output_should_match_docstring(cli_run, docstring):
        output_should_match(docstring, cli_run)

    @then(parse('the output should match "{regex}"'))
    def output_should_match(regex, cli_run):
        ...

There is possibly a way around this that is much better than what I've
done here, but this is a start at least.