CI run against latest deps is failing

[github-actions]

See https://github.com/matrix-org/synapse/actions/runs/2407332978

[DMRobertson]

 synapse/config/_util.py:59: error: Subclass of "str" and "int" cannot exist: would have incompatible method signatures  [unreachable]
synapse/config/_util.py:60: error: Statement is unreachable  [unreachable]

synapse/synapse/config/_util.py

Lines 43 to 63 in 4b965c8

	def json_error_to_config_error(
	e: jsonschema.ValidationError, config_path: Iterable[str]
	) -> ConfigError:
	"""Converts a json validation error to a user-readable ConfigError
	Args:
	e: the exception to be converted
	config_path: the path within the config file. This will be used as a basis
	for the error message.
	Returns:
	a ConfigError
	"""
	# copy `config_path` before modifying it.
	path = list(config_path)
	for p in list(e.absolute_path):
	if isinstance(p, int):
	path.append("<item %i>" % p)
	else:
	path.append(str(p))
	return ConfigError(e.message, path)

I think the underlying change was the recent types-jsonschema release, see python/typeshed#7950. The stubs now say that e.absolute_path is a Sequence[str].

[DMRobertson]

The stubs are incorrect!

import jsonschema

SCHEMA = {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "array",
    "items": {"type": "string"},
}


document = ["a", 12345, "c", "d"]

try:
    jsonschema.validate(document, SCHEMA)
except jsonschema.ValidationError as e:
    print(repr(e))
    for path_entry in e.absolute_path:
        print(repr(path_entry), type(path_entry))

python temp.py
<ValidationError: "12345 is not of type 'string'">
1 <class 'int'>

[DMRobertson]

Proposed a fix upstream at python/typeshed#7980