Update to support new cisagov/guacscanner version

🗣 Description

This PR adds support for the new version of cisagov/guacscanner and updates the tasks to install a specific version of cisagov/guacscanner.

With the changes in https://github.com/cisagov/guacscanner/pull/16 to connect to Windows instances using VNC there needs to be an additional secret for the Dockerized container version of cisagov/guacscanner. Additionally we specify the version of the Dockerized container version to install to avoid unsupported changes to a latest version from being unintentionally installed.

Automated tests work. I generated a new AMI using this branch and everything installed and worked as expected.

[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 relevant repo and/or project documentation has been updated to reflect the changes in this PR.
[x] Tests have been added and/or modified to cover the changes in this PR.
[x] All new and existing tests pass.