False negative: B501 misses `verify=False` on `requests.Session` / `httpx.Client` instance methods

Describe the bug

B501 currently detects verify=False for module-level calls like requests.get(...) and httpx.get(...), but misses equivalent insecure calls on client/session instances (for example session.get(..., verify=False)).
This creates false negatives for common usage patterns and leaves CWE-295 cases undetected.

Reproduction steps

import httpx
import requests
session = requests.Session()
session.get("https://gmail.com", timeout=30, verify=False)
session.post("https://gmail.com", timeout=30, verify=False)
with requests.Session() as scoped_session:
    scoped_session.put("https://gmail.com", timeout=30, verify=False)
    scoped_session.delete("https://gmail.com", timeout=30, verify=False)
client = httpx.Client(timeout=30)
client.get("https://gmail.com", timeout=30, verify=False)
client.post("https://gmail.com", timeout=30, verify=False)
Run:
bandit -q -r <repro_file.py> -t B501 -f json
Actual result: no B501 findings for the above calls.

Expected behavior

Six alarms should be generated.

Bandit version

1.9.1 (Default)

Python version

3.14 (Default)

Additional context

No response

Start by reproducing the B501 case with the provided requests.Session and httpx.Client examples, then trace the B501 check that handles module-level calls. Confirm the change by running the shown bandit command and verify that six B501 alarms are reported for the instance-method calls.