configure.py: Remove duplicate scylla-package.tar.gz artifact
configure.py: Remove duplicate scylla-package.tar.gz artifact

We currently keep a copy of scylla-package.tar.gz in "build/<mode>" for
compatibility. However, we've long since switched our CI system over to
the new location, so let's remove the duplicate and use the one from
"build/<mode>/dist/tar" instead.
Message-Id: <db43b7197550d87a1b3fc563e426619c6dd876cb@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla