Heroku manual deploy broken

[lucashaley]

The Ruby version you are trying to install does not exist: ruby-2.6.3
!
! Heroku recommends you use the latest supported Ruby version listed here:
! https://devcenter.heroku.com/articles/ruby-support#supported-runtimes
!
! For more information on syntax for declaring a Ruby version see:
! https://devcenter.heroku.com/articles/ruby-versions

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To Reproduce
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4. See error

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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

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• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

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