ci: Use pyenv for the lint task #26548

1. 
   maflcko commented at 3:34 pm on November 21, 2022: member

   Currently the lint task uses Ubuntu Bionic, to be able to pin the python version to 3.6. However, this is problematic:

   • While unlikely to happen soon, with the “Ubuntu Pro” stuff, it is unclear when Bionic is going to shut down
   • This requires workarounds like https://github.com/bitcoin/bitcoin/blob/0968c514015fb187b7b65575a734c0310f3a1ac0/ci/lint/04_install.sh#L12

   This should be fixed by switching to pyenv to pin the version, then bumping to Jammy to remove the git workaround.

   I am not familiar with pyenv, which is why I created this issue, but apparently it is possible, see for example https://github.com/fanquake/core-review/blob/abf055db20c388e56185404ac03c7304f3905e39/docker/lint.dockerfile#L35

   Edit: As a warning, the lint entry point is undocumented and may be unsafe, so run everything in a VM to be safe. Entry point: https://github.com/bitcoin/bitcoin/blob/01a66e21ef74bed8b6592c1ac4756114719a5949/.cirrus.yml#L76

   Useful skills:

   • Bash, Python, Pyenv, Ubuntu apt

   Want to work on this issue?

   For guidance on contributing, please read CONTRIBUTING.md before opening your pull request.

2. maflcko added the label good first issue on Nov 21, 2022
3. 
   robigan commented at 8:51 am on November 25, 2022: none

   This shouldn’t be too hard, good thing my pain and struggles with apt, VMs and python’s virutal environments finally pay off. Should be able to submit a PR soon.
4. robigan referenced this in commit b9a24e0d1f on Nov 25, 2022
5. maflcko closed this on Jan 17, 2023

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6. sidhujag referenced this in commit c4990322a2 on Jan 17, 2023
7. bitcoin locked this on Jan 17, 2024

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maflcko robigan

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