[Task] Improve "Prepare Valkey sources" of install-engine/action.yml

[affonsov]

Description

It is not necessary to check out the entire repository in order to determine the source version. We can just retrieve the version.h file, and only checkout the full repo when we need to build Valkey/Redis (i.e. when there is a cache miss). Additionally, when we do need to check out the full repo, we can do minimal, sparse checkout rather than full checkout. Both will speed up this job.

Checklist

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Additional Notes

No response