This change ports the Travis CI release workflow for macOS to Github
Actions. Note that while this is functionally identical to the
previous Travis CI flow, no work has been done to update the macOS
build scripts to build for arm64.
This Github Actions workflow uses a Linux-based running to create the
release tarball for mosh. This is necessary since mosh does not check
in the autoconf/automake generated files, so the default release
action source download is missing files that are needed for
distributions that use the upstream-provided ./configure script.
Alex Chernyakhovsky