instancer: use_NO_VARIATION_INDEX=False when optimizing {H,V}VAR VarStore
instancer: use_NO_VARIATION_INDEX=False when optimizing {H,V}VAR VarStore

Same as we do in subsetter, see https://github.com/fonttools/fonttools/pull/2662/commits/e01f643a8e41eacded24b67adb841eb0c217f43f

fonttools/fonttools,googlefonts/fonttools