Update seastar submodule
Update seastar submodule

* seastar 7a3b4b4e4e...affc3a5107 (6):
  > Merge "Add the possibility to remove rules from routes" from Pavel
  > stall_detector: expose correct clock type to use
  > queue: add has_blocked_consumer() function
  > Merge "core: reduce memory use for idle connections" from Avi
  > testing: Enable abort_on_internal_error on tests
  > core: Add a on_internal_error helper

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