internal/rosa: key-value type

This type is used very frequently. The new type is much easier to type and can receive helper methods eventually if needed.

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

internal/rosa/zlib.go

@@ -12,7 +12,7 @@ func (t Toolchain) newZlib() (pkg.Artifact, string) {
 		mustDecode(checksum),
 		pkg.TarGzip,
 	), nil, &CMakeHelper{
-		Cache: [][2]string{
+		Cache: []KV{
 			{"CMAKE_BUILD_TYPE", "Release"},
 
 			{"ZLIB_BUILD_TESTING", "OFF"},