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>

pyproject.toml

@@ -48,7 +48,7 @@ mkdocs = ">=1.4"
 parse-type = ">=0.6.0"
 poethepoet = "*"
 pytest = ">=6.2,<=8.1"
-pytest-bdd = ">=6.0"
+pytest-bdd = ">=8.0"
 pytest-clarity = "*"
 pytest-xdist = ">=2.5.0"
 requests = "*"
@@ -170,7 +170,7 @@ isolated_build = True
 [testenv]
 deps =
   pytest >=6.2,<=8.1
-  pytest-bdd >=6.0
+  pytest-bdd >=8.0
   pytest-xdist >=2.5.0
   parse-type >=0.6.0
   toml >=0.10