remove release phase from procfile

[atomfrede]

I tested it with:

• deploy via jhipster heroku and git
• add github actions integration
• failing deployment
• adapt procfile, push to github
• deployment works

Sample repo: https://github.com/atomfrede/jh-14814-sample

closes #14814

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[atomfrede]

Bounty claimed https://opencollective.com/generator-jhipster/expenses/40367