minor go cleanup and some performance improvements #3063

Job	Run time
Build melange and add to artifact cache	34s
Build packages (bubblewrap, hello-wolfi)	1m 25s
Build packages (bubblewrap, glibc)	13m 20s
Build packages (bubblewrap, tini)	1m 11s
Build packages (bubblewrap, lzo)	1m 33s
Build packages (bubblewrap, bubblewrap)	1m 27s
Build packages (bubblewrap, gitsign)	2m 37s
Build packages (bubblewrap, guac)	4m 17s
Build packages (bubblewrap, mdbook)	3m 52s
Build packages (bubblewrap, s3cmd)	1m 11s
Build packages (bubblewrap, perl-yaml-syck)	1m 27s
Build packages (bubblewrap, ncurses)	2m 23s
Build packages (qemu, hello-wolfi)	1m 53s
Build packages (qemu, glibc)	14m 7s
Build packages (qemu, tini)	2m 2s
Build packages (qemu, lzo)	1m 59s
Build packages (qemu, bubblewrap)	1m 53s
Build packages (qemu, gitsign)	3m 17s
Build packages (qemu, guac)	4m 50s
Build packages (qemu, mdbook)	4m 37s
Build packages (qemu, s3cmd)	1m 58s
Build packages (qemu, perl-yaml-syck)	1m 49s
Build packages (qemu, ncurses)	2m 46s
	1h 16m 28s

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