sdk: during wolfictl build gobump melange

[xnox]

wolfictl & melange are both built from git tip, however the former vendors the latter. Thus there can be disrepancy between the two melanges as used directly or via wolfictl. To resolve this discrepancy, always gobump melange in wolfictl prior to the build.

This will ensure SDK image is always internally consistent w.r.t. melange capabilities.