tests: remove remaining uses of sstable_assertions::make_reader_v1()
tests: remove remaining uses of sstable_assertions::make_reader_v1()

This deals with the sstable reader tests that involve range
tombstones.

Signed-off-by: Michael Livshin <ae60993c65de9cdf2ca07b7426c976808535d555@scylladb.com>

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