Validate: Failed to build module 'CouchbaseLiteSwift' from its module interface

Describe the bug
On Xcode 12.2，using cocoapods push to trunk, validating can't pass.

Error message:

• ERROR | [iOS] xcodebuild: XX/Couchbase/CBDatabase.swift:10:8:
  error: failed to build module 'CouchbaseLiteSwift' from its module interface;
  the compiler that produced it, 'Apple Swift version 5.3 (swiftlang-1200.0.29.2 clang-1200.0.30.1)',
  may have used features that aren't supported by this compiler, 'Apple Swift version 5.3.1 (swiftlang-1200.0.41 clang-1200.0.32.8)'

https://github.com/couchbase/couchbase-lite-ios/issues/2776