fix: avoid requests to invalid hostname

Implementation of `net_box` in `tarantool-module` resolves hostnames
with a `to_socket_addrs` function that is blocking. Pytest uses
fake addresses in one test, and sometimes it results in 5-second
blockage and consequent test failure.

This patch only provides a workaround. It makes a connection to fail
even before the blocking DNS request.

See also:
- https://git.picodata.io/picodata/picodata/tarantool-module/-/issues/81

test/int/test_joining.py

@@ -23,7 +23,10 @@ def fake_join(peer: Instance, id: str, timeout: float):
     args = (
         f"{id}",  # instance_id
         None,  # replicaset_id
-        f"{id}:3301",  # address
+        # Workaround slow address resolving. Intentionally use
+        # invalid address format to eliminate blocking DNS requests.
+        # See https://git.picodata.io/picodata/picodata/tarantool-module/-/issues/81
+        f"nowhere/{id}",  # address
         False,  # voter
     )
     return peer.call(".raft_join", *args, timeout=timeout)