Deprecate ssp-all-VALID.xml SSP for integration testing, replace with example SSP

[aj-stein-gsa]

This is a ...

improvement - something could be better

This relates to ...

• the FedRAMP OSCAL Validations

User Story

Per discussion with the team, with #953 merged, we have agreed to move forward with using the revised, fuller SSP example that @brian-ruf has been working on with us to drive requirement checking and flesh out the epics in #803. We will now deprecate the ssp-all-VALID.xml file and replace integration-level testing with this file to use existing data that is closer to being a full representation of valid OSCAL data for SSP before constraint definition, instead of backporting during constraint dev.

Goals

• Simplify constraint development and building example valid OSCAL that does not fail constraint violation
• Minimize merge conflicts in the valid SSP file for integration, it's one of several common locations for merge conflicts with overlapping PRs

Dependencies

• Add Example SSP #953

Acceptance Criteria

• All FedRAMP Documents Related to OSCAL Adoption (https://github.com/GSA/fedramp-automation) affected by the changes in this issue have been updated.
• A Pull Request (PR) is submitted that fully addresses the goals of this User Story. This issue is referenced in the PR.

Other information

No response