sled-agent: Remove direct dpd NAT entry creation in service zone startup path - #11073

control: job assigned to worker 01KZVV9QY1EH507TJQA0D0AXWX [factory aws, i-08ff1c99bb8e5d9a2] (queued for 50 s)
...
task: starting task 0: "setup"
task: process exited: duration 3106 ms, exit code 0
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task: starting task 1: "rust-toolchain"
task: process exited: duration 16818 ms, exit code 0
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task: starting task 2: "authentication"
task: process exited: duration 17 ms, exit code 0
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task: starting task 3: "clone repository"
task: process exited: duration 18609 ms, exit code 0
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task: starting task 4: "build"
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|  Documenting sled-hardware-types v0.1.0 (/work/oxidecomputer/omicron/sled-hardware/types)
|  Documenting omicron-workspace-hack v0.1.0 (/work/oxidecomputer/omicron/workspace-hack)
|  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 16s
|    Generated /work/oxidecomputer/omicron/target/doc/api_identity/index.html and 201 other  [...]
| 
| real     7:16.808221146
| user    19:55.711709060
| sys      4:17.160781789
| trap        0.299742645
| tflt        0.072941978
| dflt        0.133306376
| kflt        0.000036614
| lock  6:54:37.251226682
| slp   2:26:19.053532454
| lat        35.415774258
| stop     2:06.181698818
task: process exited: duration 818558 ms, exit code 0
|W| found 0 output files