CQL 3.21.0

What's Changed

• Remove type from TupleTypeElement and ChoiceType, which were deprecated by @JPercival in #1482
• Change default signature level from None to Overloads by @JPercival in #1481
• Mapping for implicit dependency on FHIR by @JPercival in #1484
• Prep for retiring Jackson-flavored ELM by @JPercival in #1485

Full Changelog: v3.20.0...v3.21.0