libcue: change module name to github.com/cue-lang/libcue

Ideally we want the module name to be `cuelang.org/c/cue`, but we
haven't set up vanity imports yet so there is no way to use `go install`.

Change module name to `github.com/cue-lang/libcue` so `go install`
works.

Signed-off-by: Aram Hăvărneanu <[email protected]>
Change-Id: Ifc8d3ced037c8eb63f7c1877187555a931cedf1c
Reviewed-on: https://review.gerrithub.io/c/cue-lang/libcue/+/1192734
Reviewed-by: Marcel van Lohuizen <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

go.mod

@@ -1,4 +1,4 @@
-module cuelang.org/c/cue
+module github.com/cue-lang/libcue
 
 go 1.22.0