Force semver() caching in build target to leave .mkit/semver

To make it easier for build tools to read full version information.

src/include/build.sh

     # Add meat to all skeletons
     #
     local srcpath   # each source path
+    semver >/dev/null
     find . -type f -name '*.skel' \
      | while read -r srcpath; do
            _build1 "$srcpath"