Fix Hard-Coded Logic in Filetype Extension Conversion Script for Pipeline

[aj-stein-nist]

Committer Notes

Closes usnistgov/oscal-content#109, with explanation in usnistgov/oscal-content#109 (comment).

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[aj-stein-nist]

Talked with Dave and will document evidence of in-place testing but not embed tests inline or separately add them and invoke them if we will not execute them as mandatory in CI/CD. Setting up CI/CD script testing and hardness would be a big lift to get it right.

[aj-stein-nist]

Woops, it took a lot of CI/CD tweaks to confirm this was working on my fork and I couldn't figure out the weird errors in the GHA itself for the auto-commit features (it doesn't work well on forks). Finally, here is a reviewable example that the tweaks worked.

https://github.com/aj-stein-nist/oscal-content/pull/1/files#diff-a3a508d3ee6d8007468e74ec6373df31844335c1b59db656872264a04b3cf53a