[BUG] SPM fails installing formula that has binary files in it

Description
SPM package containing a binary file fails to install

Setup
Amazon Linux 2 4.14.193-149.317.amzn2.x86_64
salt-api-3001.3-1.amzn2.noarch
salt-minion-3001.3-1.amzn2.noarch
salt-3001.3-1.amzn2.noarch
salt-master-3001.3-1.amzn2.noarch

Steps to Reproduce the behavior

cat > FORMULA <<EOF
name: SPM_TEST
os: Amazon
os_family: RedHat
version: 0.1
release: 1
summary: Testing SPM with binary files
description: Testing SPM with binary files
top_level_dir: spm-test
EOF

mkdir spm-test
dd if=/dev/urandom of=spm-test/spm-test.bin bs=1 count=1024
echo "# test" > spm-test/spm-test.sls

Build SPM and try to install it

spm build spm-test
spm local install -f -y /srv/spm_build/SPM_TEST-0.1-1.spm

This fails with

[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9b in position 4: invalid start byte
Traceback (most recent call last):
  File "/bin/spm", line 11, in <module>
    load_entry_point('salt==3001.3', 'console_scripts', 'spm')()

Expected behavior

Remove binary file, build SPM and install works correct

rm -f spm-test/spm-test.bin
spm build spm-test
spm local install -f -y /srv/spm_build/SPM_TEST-0.1-1.spm

Screenshots
n/a

Versions Report

Salt Version:
           Salt: 3001.3

Dependency Versions:
           cffi: Not Installed
       cherrypy: unknown
       dateutil: 2.8.1
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.5.6
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: Not Installed
   pycryptodome: 3.6.1
         pygit2: Not Installed
         Python: 3.7.9 (default, Aug 27 2020, 21:59:41)
   python-gnupg: Not Installed
         PyYAML: 4.2
          PyZMQ: 17.0.0
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.2.3

System Versions:
           dist: amzn 2
         locale: UTF-8
        machine: x86_64
        release: 4.14.193-149.317.amzn2.x86_64
         system: Linux
        version: Amazon Linux 2

Additional context
n/a

Reproduce the failure using the shown FORMULA, spm-test/spm-test.bin, and the spm build and spm local install commands, starting at the /bin/spm entry point and following the SPM build/install path. Trace where the binary content is decoded, then verify that an SPM containing the generated binary installs successfully without the UnicodeDecodeError.