internal/rosa: patch header search paths

This removes the need for reference CFLAGS in the standard toolchain.

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

internal/rosa/python.go

@@ -46,7 +46,8 @@ chmod -R +w /usr/src/python/
 export HOME="$(mktemp -d)"
 cd "$(mktemp -d)"
 /usr/src/python/configure \
-	--prefix=/system
+	--prefix=/system \
+	--build="${ROSA_TRIPLE}"
 make "-j$(nproc)"
 make test
 make DESTDIR=/work install