Use protoc x86_64 on Apple M1 aarch64

[schlosna]

Goals (and why):
==COMMIT_MSG==
Use protoc x86_64 on Apple M1 aarch64

The old protoc version 3.5.1 atlasdb uses does not yet support Apple M1 aarch64
(see protocolbuffers/protobuf#8062), so use x86_64 until
atlasdb upgrades to protoc 3.18.0+ which add osx-aarch_64.
==COMMIT_MSG==

Implementation Description (bullets): Use protoc x86_64 on Apple M1 aarch64, otherwise use protoc for default osdetector.classifier

protoc 3.18.0+ include fake osx-aarch64 binaries (e.g. protoc-3.19.2-osx-aarch_64.exe) that are really Mach-O 64-bit executable x86_64 that OSX will run in Rosetta's Intel compatible mode per protocolbuffers/protobuf#8557

Testing (What was existing testing like? What have you done to improve it?): build locally on Apple M1

Concerns (what feedback would you like?): I don't know why AtlasDB's protoc dependency is so ancient (3.5.1), but didn't want to bump it yet until understanding implications

Where should we start reviewing?:

Priority (whenever / two weeks / yesterday):

[changelog-app]

Generate changelog in changelog/@unreleased

Type

• Feature
• Improvement
• Fix
• Break
• Deprecation
• Manual task
• Migration

Description

Use protoc x86_64 on Apple M1 aarch64

The old protoc version 3.5.1 atlasdb uses does not yet support Apple M1 aarch64
(see protocolbuffers/protobuf#8062), so use x86_64 until
atlasdb upgrades to protoc 3.18.0+ which add osx-aarch_64.

Check the box to generate changelog(s)

• Generate changelog entry

[mdaudali]

Hey, thanks for this!!

Can confirm it builds on my M1, whereas develop currently doesn't (without any further changes).

We'll get someone who doesn't have an M1 to verify this change doesn't break anything for them before merging :)

[Jolyon-S]

+1 - works on an older mac too.