sstables: Remove unused includes from index_entry.hh
sstables: Remove unused includes from index_entry.hh

Signed-off-by: Vladimir Krivopalov <dc9186a06078733915a6fcbab34e59120be2b484@scylladb.com>

duarten/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,duarten/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,avikivity/scylla