Profile resolver: Compatibility with Saxon 10 and 11

[galtm]

Committer Notes

This PR addresses issue #1629 by replacing usage of document-uri with base-uri. The document-uri function is known to return different results in Saxon 10 vs. 11. Using base-uri removes a difference in the XSLT profile resolver's behavior between Saxon 10 and 11.

Unlike #1639, this PR builds on the head of the develop branch and does not include code from #1596 or #1549.

All Submissions:

• Have you selected the correct base branch per Contributing guidance?
• Have you set "Allow edits and access to secrets by maintainers"?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
  (Note: Profile resolver compatibility with Saxon 11 (on top of other unmerged PRs) #1639 has the same update, but mixed with other code. This pull request isolates the code for Saxon 11 compatibility.)
• Have you squashed any non-relevant commits and commit messages? [instructions]
• Do all automated CI/CD checks pass?

By submitting a pull request, you are agreeing to provide this contribution under the CC0 1.0 Universal public domain dedication.

Changes to Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you included examples of how to use your new feature(s)?
• Have you updated all OSCAL website and readme documentation affected by the changes you made? Changes to the OSCAL website can be made in the docs/content directory of your branch.

Testing Done

• Ran all the unit-level XSpec tests (that is, the .xspec files in the testing/ directory) with Oxygen 24.1, which uses Saxon 10.
• Ran all the unit-level XSpec tests with Oxygen 25.0, which uses Saxon 11.
• With both Oxygen 24.1 and 25, transformed all the profiles in src/specifications/profile-resolution/profile-resolution-examples. Diff'd the results, and they are the same except time stamps. The profiles that error out (e.g., broken_profile.xml) behave the same way in both Oxygen versions.
• Used the command in the "How do we replicate this issue" section of XSLT profile resolver does not work with Saxon version 11 #1629. Now the command works with Saxon 12.0.

[aj-stein-nist]

Looks good, thanks so much for your prompt turnaround given the feedback requested. I have not merged this yet, but will shortly as I do some higher-level integration testing "by hand" so to speak.