Httpx 0.28.1 ignores the cert parameter when verify is string.

[gtsystem]

Hi,
until httpx 0.27.1 I was able to combine verify and cert parameters as follow:

cert = ("path/to/cert.pem", "path/to/cert.key")
r = httpx.get("https://example.org", verify="path/to/client.pem", cert=cert)

But now the behavior change as the certicate chain is not updated.
This is visible from the code https://github.com/encode/httpx/blob/0.28.1/httpx/_config.py#L54

def create_ssl_context(
    verify: ssl.SSLContext | str | bool = True,
    cert: CertTypes | None = None,
    trust_env: bool = True,
) -> ssl.SSLContext:
   ...

    if verify is True:
       ctx = ...
    elif verify is False:
        ctx = ...
    elif isinstance(verify, str):  # pragma: nocover
        ...
        if os.path.isdir(verify):
            return ssl.create_default_context(capath=verify) # <--- returns without calling load_cert_chain
        return ssl.create_default_context(cafile=verify)  # <--- returns without calling load_cert_chain
    else:
        ctx = verify

    if cert:  # pragma: nocover
        message = (
            "`cert=...` is deprecated. Use `verify=<ssl_context>` instead,"
            "with `.load_cert_chain()` to configure the certificate chain."
        )
        warnings.warn(message, DeprecationWarning)
        if isinstance(cert, str):
            ctx.load_cert_chain(cert)
        else:
            ctx.load_cert_chain(*cert)   # <--- this line is never reached

    return ctx

I understand that setting verify to string is already deprecated and I may just going to fix the code from my side, but I have the feeling that this is a bug, as this is the only combination using return ... instead of ctx = ....

Related issue gtsystem/lightkube#78