Confirmed in 3.10 and 3.11:

>>> ast.literal_eval(r'''\
... \
... (\
... \ ''')
fish: Job 1, 'python' terminated by signal SIGSEGV (Address boundary error)

3.9 raises SyntaxError:

>>> ast.literal_eval(r'''
... \
... (\
... \ ''')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "ast.py", line 62, in literal_eval
    node_or_string = parse(node_or_string, mode='eval')
  File "ast.py", line 50, in parse
    return compile(source, filename, mode, flags,
  File "<unknown>", line 4
    \
    ^
SyntaxError: unexpected character after line continuation character