Extensions are currently only supported on linux platforms, since $vectorSearch/$search are only supported on those platforms.

We made some compromises during the implementation phase of extensions based on the assumption that we'll only support linux platforms. However, we may need to provide support for MacOS in the long term.

Investigate the work required to support extensions on MacOS on both x86 and arm.

todo items:

• GPG was brought into the build system in order to sign our test extensions and import and embed the mongot extension signing key into the server. This was only done for linux platforms. We would need to build gpg for MacOS as well, and import it into the build system.
• Extension loading is conditionally compiled in mongod_main.cpp/mongos_main.cpp. Update this to support macOS.
• Enable rnp unit tests on macos 
• enable extension unit tests and integration tests on macOS
• Note, this task does not include enabling with_mongot_extension_ suites on macOS. At the time of this writing, search extension support on these platforms is up for debate.