Add the second part of the multirack join service - #10989

control: job assigned to worker 01M0ED29CYX3S8CJX9R0KKHM3Q [factory aws, i-046bbf500c4bb49fb] (queued for 51 s)
...
task: starting task 0: "setup"
task: process exited: duration 4090 ms, exit code 0
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task: starting task 1: "rust-toolchain"
task: process exited: duration 17076 ms, exit code 0
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task: starting task 2: "authentication"
task: process exited: duration 16 ms, exit code 0
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task: starting task 3: "clone repository"
task: process exited: duration 11663 ms, exit code 0
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task: starting task 4: "build"
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| info: running `cargo check --bins` on zone-setup (337/337)
| warning: profile package spec `blake2b_simd` in profile `dev` did not match any packages
| warning: profile package spec `rust-argon2` in profile `dev` did not match any packages
|     Checking uzers v0.12.2
|     Checking zone-setup v0.1.0 (/work/oxidecomputer/omicron/zone-setup)
|     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.70s
| 
| real    14:02.686777033
| user    21:19.641473562
| sys      4:22.556417262
| trap        0.338810094
| tflt        0.580440675
| dflt        0.866017638
| kflt        0.004721240
| lock  1:29:53.339156483
| slp   1:41:03.440370082
| lat        58.232825281
| stop     4:11.606525053
task: process exited: duration 972921 ms, exit code 0
|W| found 0 output files