fix(build): download correct cloud-agent for arch

[oxy]

Fixes the npm postinstall script, which is also used to download cloud-agent, to download based on the system architecture.

[codecov]

Codecov Report

Merging #3331 (6ffe388) into main (02a0e05) will not change coverage.
The diff coverage is n/a.

❗ Current head 6ffe388 differs from pull request most recent head d54da76. Consider uploading reports for the commit d54da76 to get more accurate results

@@           Coverage Diff           @@
##             main    #3331   +/-   ##
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  Coverage   58.95%   58.95%           
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  Files          35       35           
  Lines        1703     1703           
  Branches      374      374           
=======================================
  Hits         1004     1004           
  Misses        561      561           
  Partials      138      138           

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[code-asher]

This is a big ol' nit but I'm thinking we should move this inside main to match OS.

[oxy]

Will look at it for 3.11/3.10.1 - tested this locally for both amd64/arm64, and don't want to shake things up with changes on release day