Fall back to protoc osx-x86_64 on Apple Silicon

<!-- markdown --> This change introduces and automatically applies a new profile for osx-aarch_64 hosts named `apple-silicon-workaround`. This profile overrides the property `os.detected.classifier` with the value `osx-x86_64`. The intention is that this change will permit the build to proceed with the x86 version of `protoc`, making use of the Rosetta instruction translation service built into the OS. If you'd like to provide and make use of your own aarch_64 `protoc`, you can disable this profile on the command line by adding `-P'!apple-silicon-workaround'`, or through configuration in your `settings.xml`.