Use `COPY --link` to share Go layer across OS variants / updates #450

Job	Run time
Generate Jobs	35s
1.22rc1-bookworm	53s
1.22rc1-bullseye	32s
1.22rc1-alpine3.19	26s
1.22rc1-alpine3.18	27s
1.22rc1-windowsservercore-ltsc2022, 1.22rc1-nanoserver-ltsc2022	15m 37s
1.22rc1-windowsservercore-1809, 1.22rc1-nanoserver-1809	14m 8s
1.21.6-bookworm	32s
1.21.6-bullseye	33s
1.21.6-alpine3.19	25s
1.21.6-alpine3.18	28s
1.21.6-windowsservercore-ltsc2022, 1.21.6-nanoserver-ltsc2022	13m 19s
1.21.6-windowsservercore-1809, 1.21.6-nanoserver-1809	9m 23s
1.20.13-bookworm	31s
1.20.13-bullseye	37s
1.20.13-alpine3.19	2m 5s
1.20.13-alpine3.18	2m 5s
1.20.13-windowsservercore-ltsc2022, 1.20.13-nanoserver-ltsc2022	15m 6s
1.20.13-windowsservercore-1809, 1.20.13-nanoserver-1809	13m 31s
1.20.13-bookworm (force build)	2m 26s
1.20.13-bullseye (force build)	2m 28s
1.20.13-alpine3.19 (force build)	2m 7s
1.20.13-alpine3.18 (force build)	2m 8s
1.22rc1-bookworm (i386)	35s
1.22rc1-bullseye (i386)	34s
1.22rc1-alpine3.19 (i386)	25s
1.22rc1-alpine3.18 (i386)	37s
1.21.6-bookworm (i386)	34s
1.21.6-bullseye (i386)	38s
1.21.6-alpine3.19 (i386)	25s
1.21.6-alpine3.18 (i386)	31s
1.20.13-bookworm (i386)	47s
1.20.13-bullseye (i386)	34s
1.20.13-alpine3.19 (i386)	2m 37s
1.20.13-alpine3.18 (i386)	2m 22s
	1h 51m 1s

Provide feedback