[Feature] Upgrade from Heroku-18 stack to Heroku-20 stack

[TimidRobot]

Problem

Excerpt from #122 Deployed to Production:

remote: This app is using the Heroku-18 stack, which is supported until April 30th, 2023.
remote: A newer stack is available: Heroku-20. To upgrade, see:
remote: https://devcenter.heroku.com/articles/upgrading-to-the-latest-stack

Description

Upgrade from Heroku-18 stack to Heroku-20 stack

Alternatives

• Wait for Heroku-22 stack (expected to be released in April of this year)

Additional context

• Upgrading to the Latest Stack | Heroku Dev Center
  • Heroku-18 Stack | Heroku Dev Center

    Heroku-18 is based on Ubuntu 18.04. It will be supported through April 2023.

  • Heroku-20 Stack | Heroku Dev Center

    Heroku-20 is based on Ubuntu 20.04. It will be supported through April 2025

[TimidRobot]

Set Stack to Heroku 20

heroku stack:set heroku-20 -a fast-eyrie-10628

Setting stack to heroku-20... done
You will need to redeploy ⬢ fast-eyrie-10628 for the change to take effect.
Run git push heroku main to trigger a new build on ⬢ fast-eyrie-10628.

git commit --allow-empty -m "Upgrading to heroku-20"

[main f318760] Upgrading to heroku-20

Deployed to Production

git push heroku main

remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Building on the Heroku-20 stack
remote: -----> Using buildpack: heroku/python
remote: -----> Python app detected
remote: -----> Using Python version specified in Pipfile.lock
remote: -----> Stack has changed from heroku-18 to heroku-20, clearing cache
remote: cp: cannot stat '/tmp/build_f7eb2fc4/requirements.txt': No such file or directory
remote: -----> Installing python-3.9.10
remote: -----> Installing pip 21.3.1, setuptools 57.5.0 and wheel 0.37.0
remote: -----> Installing dependencies with Pipenv 2020.11.15
remote:        Installing dependencies from Pipfile.lock (bce026)...
remote:        Collecting pillow==9.0.1
remote:          Downloading Pillow-9.0.1-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (4.3 MB)
remote:        Installing collected packages: pillow
remote:        WARNING: Ignoring invalid distribution -etuptools (/tmp/build_f7eb2fc4/.heroku/python/lib/python3.9/site-packages)
remote:        Successfully installed pillow-9.0.1
remote: -----> Installing SQLite3
remote: -----> $ python manage.py collectstatic --noinput
remote:        397 static files copied to '/tmp/build_f7eb2fc4/staticfiles', 705 post-processed.
remote: 
remote: -----> Discovering process types
remote:        Procfile declares types -> release, web
remote: 
remote: -----> Compressing...
remote:        Done: 96.6M
remote: -----> Launching...
remote:  !     Release command declared: this new release will not be available until the command succeeds.
remote:        Released v23
remote:        https://fast-eyrie-10628.herokuapp.com/ deployed to Heroku
remote: 
remote: Verifying deploy... done.
remote: Running release command...
remote: 
remote: Operations to perform:
remote:   Apply all migrations: admin, auth, contenttypes, legal_db, sessions, taggit
remote: Running migrations:
remote:   No migrations to apply.
remote: Waiting for release.... done.
To heroku.com:fast-eyrie-10628.git
   0a5ca9d..f318760  main -> main