Fix heroku buildpack order

[compwron]

see heroku error

###### WARNING:
       Installing a default version (20.9.0) of Node.js.
       This version is not pinned and can change over time, causing unexpected failures.
       
       Heroku recommends placing the `heroku/nodejs` buildpack in front of
       `heroku/ruby` to install a specific version of node:
       
       https://devcenter.heroku.com/articles/ruby-support#node-js-support
###### WARNING:
       Installing a default version (1.22.19) of Yarn
       This version is not pinned and can change over time, causing unexpected failures.
       
       Heroku recommends placing the `heroku/nodejs` buildpack in front of the `heroku/ruby`
       buildpack as it offers more comprehensive Node.js support, including the ability to
       customise the Node.js version:
       
       https://devcenter.heroku.com/articles/ruby-support#node-js-support

[github-actions]

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[github-actions]

This issue has been inactive for 364 hours (15.17 days) and is past the limit of 360 hours (15.00 days) so is being unassigned.You’ve just been unassigned from this ticket due to inactivity – but feel free to pick it back up (or a new one!) in the future! Thank you again for your contribution to this project.

[compwron]

not essential, trivial effort if I'm on the right computer, but only a heroku admin can do it - feel free to close this, it was for my personal tracking oops