tests: add reproducer for issue #614 Bad file descriptor on SSL topology change

Add integration test that reproduces the '[Errno 9] Bad file descriptor'
error in ControlConnection._try_connect() when TLS/SSL is enabled and
topology changes happen concurrently with active sessions.

Root cause: CPython bug python/cpython#148594
ERR_clear_error() not called before SSL_read_ex()/SSL_write_ex(), causing
stale OpenSSL error queue entries to corrupt SSL_get_error() on connections
sharing the same thread (libev event loop). Affects Python 3.12+.

Test scenarios:
- Node stop during active SSL session (primary reproducer)
- Rolling restart with continuous workload
- Decommission with active session
- Rapid node cycling stress test
- Environment diagnostic info

Run with:
  EVENT_LOOP_MANAGER=libev SCYLLA_VERSION=release:2025.2 \
  uv run pytest tests/integration/long/test_ssl_topology_change.py -v

Refs: #614, python/cpython#148594

Author: fruch