Update the `tag.sh` script to use the project version

[mcdonnnj]

🗣 Description

This pull request updates the tag.sh helper script to use the project version for the version tag being created.

💭 Motivation and context

Currently the tag.sh helper script does not specify what version to use and thus cannot get a usable version from the bump_version.sh helper script.

🧪 Testing

Automated tests pass. I verified that the tag.sh script gets the expected version.

✅ Pre-approval checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All new and existing tests pass.