fix(bundler): Use arch instead of llvm_target. fix #3285

[JonasKruckenberg]

The llvm target misidentified the arch on apple silicon, causing sidecar bundling to fail.
This fixes #3285.

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

Other information

[lucasfernog]

I see you didn't change the command to rustc --print cfg as stated on the issue. Is that intentional?

[JonasKruckenberg]

I see you didn't change the command to rustc --print cfg as stated on the issue. Is that intentional?

nope, just didn't get to it yet bc the parsing is a bit more involved