fix: use connection mode override function in config (#775)

fix #774

Author: alexanderankin

Diff for: core/testcontainers/core/config.py

@@ -106,7 +106,7 @@ class TestcontainersConfiguration:
     tc_properties: dict[str, str] = field(default_factory=read_tc_properties)
     _docker_auth_config: Optional[str] = field(default_factory=lambda: environ.get("DOCKER_AUTH_CONFIG"))
     tc_host_override: Optional[str] = TC_HOST_OVERRIDE
-    connection_mode_override: Optional[ConnectionMode] = None
+    connection_mode_override: Optional[ConnectionMode] = field(default_factory=get_user_overwritten_connection_mode)
 
     """
     https://github.com/testcontainers/testcontainers-go/blob/dd76d1e39c654433a3d80429690d07abcec04424/docker.go#L644

Diff for: core/tests/test_config.py

@@ -3,6 +3,7 @@
 from testcontainers.core.config import (
     TestcontainersConfiguration as TCC,
     TC_FILE,
+    TestcontainersConfiguration,
     get_user_overwritten_connection_mode,
     ConnectionMode,
     get_docker_socket,
@@ -81,6 +82,7 @@ def test_invalid_connection_mode(monkeypatch: pytest.MonkeyPatch) -> None:
 def test_valid_connection_mode(monkeypatch: pytest.MonkeyPatch, mode: str, use_mapped: bool) -> None:
     monkeypatch.setenv("TESTCONTAINERS_CONNECTION_MODE", mode)
     assert get_user_overwritten_connection_mode().use_mapped_port is use_mapped
+    assert TestcontainersConfiguration().connection_mode_override.use_mapped_port is use_mapped
 
 
 def test_no_connection_mode_given(monkeypatch: pytest.MonkeyPatch) -> None: