Update pytest-bdd to v8.0 (#1955)

* Encapsulate all multiline strings in triple-quotes in Gherkin files

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

* Remove comments in Gherkin files causing test breakage

These comments break the step matching.

* Fix compatibility of step-functions matching on multiple lines

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.

* Update version requirement of pytest-bdd to >=8.0

* Update tox config to match poetry config

---------

Co-authored-by: Micah Jerome Ellison <micah.jerome.ellison@gmail.com>

tests/lib/when_steps.py

@@ -34,7 +34,11 @@ all_input = '("(?P<all_input>[^"]*)")'
 # an empty line of input internally for testing purposes.
 
 
-@when(parse('we run "jrnl {command}" and {input_method}\n{all_input}'))
+@when(re(f'we run "jrnl {command}" and {input_method}'))
+def we_run_jrnl_docstring(capsys, keyring, request, command, input_method, docstring):
+    we_run_jrnl(capsys, keyring, request, command, input_method, docstring)
+
+
 @when(re(f'we run "jrnl ?{command}" and {input_method} {all_input}'))
 @when(re(f'we run "jrnl {command}"(?! and)'))
 @when('we run "jrnl"')