Remove check_remote_connectivity related  methods

As tempest.scenario.manager was announced stable interface in Tempest 27.0.0[1] it can be now reused in plugins.

Replaced methods:
	* _check_remote_connectivity
	* check_remote_connectivity (not used)

Etherpad concerning this effort:
https://etherpad.opendev.org/p/tempest-scenario-manager-cleanup

[1] https://docs.openstack.org/releasenotes/tempest/v27.0.0.html#release-notes-27-0-0

Change-Id: Idd323660b21ea109d5f24efc0edab216723c8dca
diff --git a/manila_tempest_tests/tests/scenario/manager.py b/manila_tempest_tests/tests/scenario/manager.py
index 4df0023..881cf5f 100644
--- a/manila_tempest_tests/tests/scenario/manager.py
+++ b/manila_tempest_tests/tests/scenario/manager.py
@@ -212,50 +212,6 @@
             self._log_net_info(e)
             raise
 
-    def _check_remote_connectivity(self, source, dest, should_succeed=True,
-                                   nic=None):
-        """assert ping server via source ssh connection
-
-        Note: This is an internal method.  Use check_remote_connectivity
-        instead.
-
-        :param source: RemoteClient: an ssh connection from which to ping
-        :param dest: and IP to ping against
-        :param should_succeed: boolean should ping succeed or not
-        :param nic: specific network interface to ping from
-        """
-        def ping_remote():
-            try:
-                source.ping_host(dest, nic=nic)
-            except lib_exc.SSHExecCommandFailed:
-                LOG.warning('Failed to ping IP: %s via a ssh connection '
-                            'from: %s.', dest, source.ssh_client.host)
-                return not should_succeed
-            return should_succeed
-
-        return test_utils.call_until_true(ping_remote,
-                                          CONF.validation.ping_timeout,
-                                          1)
-
-    def check_remote_connectivity(self, source, dest, should_succeed=True,
-                                  nic=None):
-        """assert ping server via source ssh connection
-
-        :param source: RemoteClient: an ssh connection from which to ping
-        :param dest: and IP to ping against
-        :param should_succeed: boolean should ping succeed or not
-        :param nic: specific network interface to ping from
-        """
-        result = self._check_remote_connectivity(source, dest, should_succeed,
-                                                 nic)
-        source_host = source.ssh_client.host
-        if should_succeed:
-            msg = ("Timed out waiting for %s to become reachable from %s"
-                   % (dest, source_host))
-        else:
-            msg = "%s is reachable from %s" % (dest, source_host)
-        self.assertTrue(result, msg)
-
     def _create_security_group(self, security_group_rules_client=None,
                                tenant_id=None,
                                namestart='secgroup-smoke',