internal/rosa/meson: disallow download

This will fail and waste time on KindExec, and cause nondeterminism in KindExecNet.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/meson.go

@@ -114,6 +114,7 @@ cd "$(mktemp -d)"
 meson setup \
 	` + strings.Join(slices.Collect(func(yield func(string) bool) {
 		for _, v := range append([]KV{
+			{"wrap-mode", "nodownload"},
 			{"prefix", "/system"},
 			{"buildtype", "release"},
 		}, attr.Setup...) {