## Problem
Action `run-python-test-set` fails if it is not used for `regress_tests`
on release PR, because it expects
`test_compatibility.py::test_create_snapshot` to generate a snapshot,
and the test exists only in `regress_tests` suite.
For example, in https://github.com/neondatabase/neon/pull/9291
[`test-postgres-client-libs`](https://github.com/neondatabase/neon/actions/runs/11209615321/job/31155111544)
job failed.
## Summary of changes
- Add `skip-if-does-not-exist` input to `.github/actions/upload` action
(the same way we do for `.github/actions/download`)
- Set `skip-if-does-not-exist=true` for "Upload compatibility snapshot"
step in `run-python-test-set` action
In future we may want to run periodic tests on dedicated cloud instances
that are not GitHub action runners.
To allow these to download artifact binaries for a specific commit hash
we want to make the search by commit hash possible and prefix the S3
objects with
`artifacts/${GITHUB_SHA}/${GITHUB_RUN_ID}/${GITHUB_RUN_ATTEMPT}`
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>