tools: set arch in Distribution.xml

refs: https://github.com/nodejs/node/pull/37678#issuecomment-821179247

We overwrite the Distribution.xml file inside the pkg which means
the pkg cannot be opened on apple silicon without rosetta
as it defaults to x86_64

PR-URL: https://github.com/nodejs/node/pull/38261


Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>