crimson/net: don't throw on failure when renewing tickets and keyrings

crimson/net: don't throw on failure when renewing tickets and keyrings

In the classical `MonClient` renewal of tickets and rotating
secrets, generally speaking, doesn't verify the `MAuthReply`.
The only difference is breaking the renewal loop:

```cpp
void MonClient::_finish_auth(int auth_err)
{
  // ...
  if (!auth_err && active_con) {
    ceph_assert(auth);
    _check_auth_tickets();
  }
  // ...
}
```

However, `crimson::mon::Client` throws `error::negotiation_failure`
which is finally handled in `Gated::dispatch()`. As the handler
there doesn't expect this particular error, it aborts the entire
process. This was the reason for failing one of the jobs at Sepia:

```
rzarzynski@teuthology:/a/rzarzynski-2022-08-01_11:01:29-crimson-rados-main-distro-default-smithi/6954468$ less ./remote/smithi174/log/ceph-osd.1.log.gz
...
DEBUG 2022-08-01 11:26:13,772 [shard 0] monc - renew_rotating_keyring secrets are up-to-date (they expire after 1659353143.772506)
INFO  2022-08-01 11:26:13,772 [shard 0] monc - renew_tickets: retrieving new tickets
INFO  2022-08-01 11:26:13,772 [shard 0] monc - sending auth(proto 2 132 bytes epoch 0) v1
INFO  2022-08-01 11:26:13,772 [shard 0] monc - waiting
INFO  2022-08-01 11:26:13,773 [shard 0] monc - handle_auth_reply mon v2:172.21.15.174:6802/101543 => v2:172.21.15.174:3300/0 returns auth_reply(proto 2 0 (0) Success) v1: 0
INFO  2022-08-01 11:26:13,773 [shard 0] monc - handle_auth_reply
INFO  2022-08-01 11:26:13,773 [shard 0] monc - renew_tickets: retrieving new tickets
INFO  2022-08-01 11:26:13,773 [shard 0] monc - sending auth(proto 2 132 bytes epoch 0) v1
DEBUG 2022-08-01 11:26:13,773 [shard 0] monc - renew_rotating_keyring secrets are up-to-date (they expire after 1659353143.7732666)
INFO  2022-08-01 11:26:13,773 [shard 0] monc - waiting
INFO  2022-08-01 11:26:13,773 [shard 0] monc - do_auth_single: mon v2:172.21.15.174:6802/101543 => v2:172.21.15.174:3300/0 returns auth_reply(proto 2 0 (0) Success) v1: 0
INFO  2022-08-01 11:26:13,773 [shard 0] monc - handle_auth_reply mon v2:172.21.15.174:6802/101543 => v2:172.21.15.174:3300/0 returns auth_reply(proto 2 0 (0) Success) v1: 0
INFO  2022-08-01 11:26:13,773 [shard 0] monc - handle_auth_reply
INFO  2022-08-01 11:26:13,773 [shard 0] monc - do_auth_single: mon v2:172.21.15.174:6802/101543 => v2:172.21.15.174:3300/0 returns auth_reply(proto 2 0 (0) Success) v1: 0
WARN  2022-08-01 11:26:13,773 [shard 0] auth - cephx client: could not verify service_ticket reply
ERROR 2022-08-01 11:26:13,773 [shard 0] monc - do_auth_single: got error -13 on mon v2:172.21.15.174:3300/0
DEBUG 2022-08-01 11:26:13,773 [shard 0] monc - renew_tickets: don't need new tickets
DEBUG 2022-08-01 11:26:13,774 [shard 0] monc - renew_rotating_keyring secrets are up-to-date (they expire after 1659353143.773988)
ERROR 2022-08-01 11:26:13,774 [shard 0] osd - mon.osd.1 dispatch() ms_dispatch caught exception: std::system_error (error crimson::net:3, negotiation failure)
```

```
2022-08-01T11:26:13.798 INFO:tasks.ceph.osd.1.smithi174.stderr:ceph-osd: /home/jenkins-build/build/workspace/ceph-dev-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/giga
ntic/release/17.0.0-13947-g4f4eedf5/rpm/el8/BUILD/ceph-17.0.0-13947-g4f4eedf5/src/crimson/common/gated.h:36: crimson::common::Gated::dispatch<crimson::mon::Client::ms_dispatch(crimson::net::ConnectionRef, MessageRef)::<lambda()>&, crimson::mon::Client>(const char*, crimson::mon::Client&, crimson::mon::Client::ms_dispatch(crimson::net::ConnectionRef, MessageRef)::<lambda()>&)::<lambda(std::__exception_ptr::exception_ptr)>: Assertion `*eptr.__cxa_exception_type() == typeid(seastar::gate_closed_exception)' failed.
2022-08-01T11:26:13.811 INFO:tasks.ceph.osd.1.smithi174.stderr:Aborting on shard 0.
```

```cpp
class Gated {
  // ...
  template <typename Func, typename T>
  inline seastar::future<> dispatch(const char* what, T& who, Func&& func) {
    return seastar::with_gate(pending_dispatch, std::forward<Func>(func)
    ).handle_exception([what, &who] (std::exception_ptr eptr) {
      if (*eptr.__cxa_exception_type() == typeid(system_shutdown_exception)) {
        gated_logger().debug(
            "{}, {} skipped, system shutdown", who, what);
        return;
      }
      gated_logger().error(
          "{} dispatch() {} caught exception: {}", who, what, eptr);
      assert(*eptr.__cxa_exception_type()
        == typeid(seastar::gate_closed_exception));
    });
  }
```

See: http://pulpito.front.sepia.ceph.com/rzarzynski-2022-08-01_11:01:29-crimson-rados-main-distro-default-smithi/6954468/

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>