Unused imports, unused variables and such.
Initially, there were no functional changes, just to get rid of some standard CodeQL warnings.
I've then broken the CI, as apparently there's a install time(!?) Python script creation for the sole purpose of product
naming. I changed it - we have it in etcdir, as SCYLLA-PRODUCT-FILE.
So added (copied from a different script) a get_product() helper function in scylla_util.py and used it instead.
While at it, also fixed the too broad import from scylla_util, which 'forced' me to also fix other specific imports (such as shutil).
Improvement - no need to backport.
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#27883