ci: use gh app to generate token rather than classic token

[kelly-sovacool]

Changes

Switch from using a classic token for gh authentication to generating one with the CCBR-bot app.

@kopardev can you install the CCBR-bot and set the app ID variable and private key secret for each of these organizations? instructions here: https://ccbr.github.io/actions/gh-app-auth.html

• abcsFrederick
• CCRGeneticsBranch
• NCIPangea
• NCI-CCR-POB
• NCI-CCDI
• NCI-RBL

Issues

see also NCI-RBL/.github#1

PR Checklist

(Strikethrough any points that are not applicable.)

• This comment contains a description of changes with justifications, with any relevant issues linked.
• [ ] Write unit tests for any new features, bug fixes, or other code changes.
• [ ] Update docs if there are any API changes.
• [ ] Update CHANGELOG.md with a short description of any user-facing changes and reference the PR number. Guidelines: https://keepachangelog.com/en/1.1.0/

[kopardev]

@kelly-sovacool ... Done! Please check.