Clean up syntax warnings

Tested with py3.13b2-nogil

```py
> jhack replay install hexanator/0
/home/dima.linux/code/jhack/jhack/utils/integrate.py:351: SyntaxWarning: invalid escape sequence '\['
print(f"{ep1} {sym}-\[{interface}]-{sym} {ep2}")
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:221: SyntaxWarning: invalid escape sequence '\S'
"^(?P\S+): (?P\S+(\s*\S+)?) (?P\S+) "
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:222: SyntaxWarning: invalid escape sequence '\.'
"unit\.(?P\S+)\.juju-log "
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:224: SyntaxWarning: invalid escape sequence '\S'
base_relation_pattern = base_pattern + "(?P\S+):(?P\S+): "
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:226: SyntaxWarning: invalid escape sequence '\S'
operator_event_suffix = "Charm called itself via hooks/(?P\S+)\."
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:229: SyntaxWarning: invalid escape sequence '\S'
event_suffix = "Emitting Juju event (?P\S+)\."
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:234: SyntaxWarning: invalid escape sequence '\S'
jhack_fire_evt_suffix = "The previous (?P\S+) was fired by jhack\."
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:237: SyntaxWarning: invalid escape sequence '\S'
"(?P\S+) \((?P\S+(\s*\S+)?)\)"
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:238: SyntaxWarning: invalid escape sequence '\.'
" was replayed by jhack\."
/home/dima.linux/code/jhack/jhack/utils/tail_charms.py:272: SyntaxWarning: invalid escape sequence '\/'
"(?:selective|full) lobotomy ACTIVE: event hooks\/(?P\S+) ignored."
/home/dima.linux/code/jhack/jhack/utils/sync.py:121: SyntaxWarning: invalid escape sequence '\.'
include_files: str = ".*\.py$",
/home/dima.linux/code/jhack/jhack/utils/nuke.py:33: SyntaxWarning: invalid escape sequence '\_'
NUKE_ASCII_ART = """
```

Start with the warning locations in jhack/utils/integrate.py, tail_charms.py, sync.py, and nuke.py, then reproduce them with the reported jhack replay install hexanator/0 command under Python 3.13. Done means the listed SyntaxWarnings no longer appear while the affected behavior and tests remain intact.

Written by the indexing model from the issue text.