Update script dependencies and update fn calls to match

[komish]

Context:

I'm looking to enable dependabot for this repository soon. Before that happens, I ran dependabot in a fork and ran the E2E testing to see how it behaved. It's look all green after a couple of signature changes (captured here), so I think this should be in good shape.

Please keep an eye out for anything strange that we think may be a result of these dependency changes. Several packages iterated major versions.

Dependabot enablement will happen later, along with syft/grype.

Summary:

• Update dependencies as dependabot would
• Remove pytest-forked and pytest-xdist, which we aren't using (since the move to behave) and were pulling in a dependency we don't need (py).
• Update method calls that were renamed between a package version update.

[komish]

@komish LGTM...but as a side question, I suppose only semver.isvalid needed changing in our code?

Correct. Did I change it somewhere unexpected or miss a spot?