Bump build/metaschema-xslt from 7d9fbfa to 16c8b0c

Bumps [build/metaschema-xslt](https://github.com/usnistgov/metaschema-xslt) from `7d9fbfa` to `16c8b0c`.
- [Commits](usnistgov/metaschema-xslt@7d9fbfa...16c8b0c)

---
updated-dependencies:
- dependency-name: build/metaschema-xslt
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>