chore(flake): update build-go-cache for less rebuild

[zimbatm]

Why

This is a small developer UX issue. In some cases, Nix would rebuild instead of fetching the result from the binary cache.

What changed

numtide/build-go-cache#9

Thanks to katexochen for fixing this issue.

Test plan

Describe what you did to test this change to a level of detail that allows your reviewer to test it

[katexochen]

@zimbatm there is actually a workaround in place to prevent the rebuilds in another way (the comment pointed me to the problem in the first place):

upm/nix/upm/default.nix

Lines 16 to 20 in 91c21f5

	# FIXME: Somehow we get cache invalidation everytime if we don't do this, also it uses a source filter
	src = runCommand "go-mod" {} ''
	install -D ${../../go.mod} $out/go.mod
	install -D ${../../go.sum} $out/go.sum
	'';

This could be removed now. :)

[blast-hardcheese]

Based on the conversation here it seems this is not necessary, closing this out for now but please feel free to follow up if I misunderstood. Thank you!