finance/quantlib: Update to 1.38

Changelogs:
https://github.com/lballabio/QuantLib/releases/tag/v1.33
https://github.com/lballabio/QuantLib/releases/tag/v1.34
https://github.com/lballabio/QuantLib/releases/tag/v1.35
https://github.com/lballabio/QuantLib/releases/tag/v1.36
https://github.com/lballabio/QuantLib/releases/tag/v1.37
https://github.com/lballabio/QuantLib/releases/tag/v1.38

Also make the THREAD_SAFE_OBSERVER_PATTERN a default.
This option is required for Java (and CSharp) bindings to work safely,
so enable it by default.

PR: 285337