auth.user's ssh signing keys operations #1569

Job	Run time
clippy	1m 9s
wasm-build	42s
build (stable, ubuntu)	4m 2s
build (stable, ubuntu, -F stream)	3m 59s
build (stable, macos)	3m 3s
build (stable, macos, -F stream)	3m 41s
build (stable, windows)	7m 42s
build (stable, windows, -F stream)	8m 10s
build (beta, ubuntu)	3m 45s
build (beta, ubuntu, -F stream)	3m 57s
build (beta, macos)	3m 3s
build (beta, macos, -F stream)	2m 47s
build (beta, windows)	6m 54s
build (beta, windows, -F stream)	7m 15s
build (nightly, ubuntu)	2m 58s
build (nightly, ubuntu, -F stream)	3m 6s
build (nightly, macos)	2m 58s
build (nightly, macos, -F stream)	3m 45s
build (nightly, windows)	6m 48s
build (nightly, windows, -F stream)	6m 34s
	1h 26m 18s

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