[Bug]: `py_test` / `py_binary` incorrectly handle an `exec_properties` attribute that is explicitly set to `None`

[bd-tkoolen]

What happened?

If exec_properties for a py_binary or py_test is explicitly set to None, an error of the form

Error: 'NoneType' value has no field or method 'items'

is raised on this line:

rules_py/py/defs.bzl

Line 67 in 5968bcb

non_test_exec_properties = {k: v for k, v in exec_properties.items() if not k.startswith("test.")}

In our case, the explicit value of None came from a symbolic macro that used inherit_attrs = "common". This regression was found when trying upgrade from version 1.3.2 to version 1.6.0. Our workaround is to use

if kwargs.get("exec_properties", None) == None:
        kwargs["exec_properties"] = {}

in symbolic macro implementations that create py_* targets.

This regression appears to have been introduced in #529; CC @keith.

Version

Development (host) and target OS/architectures: irrelevant

Output of bazel --version: bazel 8.1.1

Version of the Aspect rules, or other relevant rules from your
WORKSPACE or MODULE.bazel file: 1.6.0

Language(s) and/or frameworks involved: irrelevant

How to reproduce

py_binary(
    name = "foo",
    srcs = ["foo.py"],
    exec_properties = None,
)

Any other information?

No response