Log Message:
py-ncclient: update to 0.6.15.

    reading correct user known_hosts files by @martin-volf in #517
    fix coveralls reporting by @martin-volf in #519
    Agent key selection by @aahoward in #522
    Update session.py - Parameterize timeout for _post_connect by @GerriorL in #543
    update comment in _parse11 by @mercimat in #549
    Fix missing timeout in ssh post_connect by @GerriorL in #550
    Migrate from nose to pytest by @einarnn in #555
    Based on v0 6 13 fix for deprecation warnings threading thread by @slieberth \ 
in #553
    Introduce support for TLS by @ivandkhn in #556
    remove - version of setting and replace with _ version by @einarnn in #562
    permissive UTF-8 parsing for NC11 delimiter by @einarnn in #563
    introduce python3.12 for ci by @einarnn in #568
    Add commit comment capability support for SROS devices in ncclient by \ 
@torkashvand in #574