Clarify authz comments - #11028

control: job assigned to worker 01KZF1Q7ZTX11HSZGJ4W3RSCAP [factory aws, i-0c10af5c887969fdf] (queued for 54 s)
...
task: starting task 0: "setup"
task: process exited: duration 4115 ms, exit code 0
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task: starting task 1: "rust-toolchain"
task: process exited: duration 16599 ms, exit code 0
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task: starting task 2: "authentication"
task: process exited: duration 24 ms, exit code 0
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task: starting task 3: "clone repository"
task: process exited: duration 12438 ms, exit code 0
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task: starting task 4: "build"
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| + unset TMPDIR
| + echo 'files in /var/tmp/omicron_tmp (none expected on success):'
| files in /var/tmp/omicron_tmp (none expected on success):
| + find /var/tmp/omicron_tmp -ls
| 134941   32 drwxr-xr-x   2 build    build           2 Aug  7 21:56 /var/tmp/omicron_tmp
| + rmdir /var/tmp/omicron_tmp
task: process exited: duration 1943915 ms, exit code 0
|W| found 6 output files
|W| uploading: /work/cargo-build-analysis.jsonl (1805471 bytes)
|W| uploaded: /work/cargo-build-analysis.jsonl
|W| uploading: /work/environment.json (108 bytes)
|W| uploaded: /work/environment.json
|W| uploading: /work/oxidecomputer/omicron/target/nextest/ci/junit.xml (653434 bytes)
|W| uploaded: /work/oxidecomputer/omicron/target/nextest/ci/junit.xml
|W| uploading: /work/oxidecomputer/omicron/target/live-tests-archive.tgz (280543744 bytes)
|W| uploaded: /work/oxidecomputer/omicron/target/live-tests-archive.tgz
|W| uploading: /tmp/nextest-run-archive.zip (3154870 bytes)
|W| uploaded: /tmp/nextest-run-archive.zip
|W| uploading: /tmp/nextest-chrome-trace.json (4159260 bytes)
|W| uploaded: /tmp/nextest-chrome-trace.json