Update Version Number from 0.3.0 to 0.4.0 (Driftwood)

[rlxdev]

🗣 Description

Version number updated to 0.4.0 in preparation for the Driftwood release.

Closes #566

🧪 Testing

Ran ScubaGoggles to confirm that updated version number appears in reports.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• If applicable, All future TODOs are captured in issues, which are referenced in the PR description.
• The relevant issues PR resolves are linked preferably via closing keywords.
• All relevant type-of-change labels have been added.
• I have read and agree to the CONTRIBUTING.md document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge Checklist

• This PR has been smoke tested to ensure main is in a functional state when this PR is merged.
• Squash all commits into one PR level commit using the Squash and merge button.

✅ Post-merge Checklist

• Delete the branch to clean up.
• Close issues resolved by this PR if the closing keywords did not activate.

[mitchelbaker-cisa]

Looks good.

• Installed new version of scubagoggles, successfully installed v0.4.0 (listed under pip list in venv)
• Created new scubagoggles report and v0.4.0 is indicated in BaselineReports.html; checked ScubaResults.json for any lingering references to v0.3.0 and found none.

[snarve]

Looks good! Updated version showing up as expected after reinstalling the dependencies.