[reconfigurator] background task for marking VMMs to be stopped for update - #11170

control: job assigned to worker 01M113V5EKHX4YZX4MCF6R24S0 [factory aws, i-0ff62de25c788442a] (queued for 50 s)
...
task: starting task 0: "setup"
task: process exited: duration 4087 ms, exit code 0
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task: starting task 1: "rust-toolchain"
task: process exited: duration 14897 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 13537 ms, exit code 0
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task: starting task 4: "build"
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|  Documenting omicron-uuid-kinds v0.1.0 (/work/oxidecomputer/omicron/uuid-kinds)
|  Documenting dev-tools-common v0.1.0 (/work/oxidecomputer/omicron/dev-tools/common)
|     Finished `dev` profile [unoptimized + debuginfo] target(s) in 7m 41s
| warning: the following packages contain code that will be rejected by a future version of  [...]
| note: to see what the problems were, use the option `--future-incompat-report`, or run `ca [...]
|    Generated /work/oxidecomputer/omicron/target/doc/api_identity/index.html and 206 other  [...]
| 
| real     7:42.002183409
| user    20:35.679600401
| sys      4:24.323132954
| trap        0.290097163
| tflt        0.008573855
| dflt        0.140721005
| kflt        0.000039440
| lock  7:23:50.221235101
| slp   2:35:41.850332163
| lat        34.029429025
| stop     2:08.915140100
task: process exited: duration 854316 ms, exit code 0
|W| found 0 output files