spacemacs/dump-vars-to-file: don't visit dump file
spacemacs/dump-vars-to-file: don't visit dump file

Visiting the dump file before writing to it is slow, because it triggers
all the regular actions that happen when a user opens a file, e.g.
enable major mode and minor modes. We don't need all that,
with-temp-file is what we really want.

tsonntag/dotemacs,tsonntag/dotemacs,tsonntag/dotemacs,tsonntag/dotemacs