fix(mypy): silence Optional[str] arg-type in switch_org, not cast

Guard baseline already sat at max cast() count; cast() would've pushed it
over. Use a localized type: ignore instead, per DEVELOP.md guidance.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GgDZr3AgU9uKz5EWcVZZVY

Author: vaimdev

graphistry/pygraphistry.py

@@ -2699,7 +2699,9 @@ def personal_key_secret(self, value: Optional[str] = None):
     def switch_org(self, value: str):
         org_name = value.strip()
         try:
-            switch_org_request(self._base_url(), org_name, self.api_token(), self.session.certificate_validation)
+            switch_org_request(
+                self._base_url(), org_name, self.api_token(), self.session.certificate_validation  # type: ignore[arg-type]
+            )
         except (OrgSwitchError, OrgSwitchIdpChallenge) as exc:
             raise Exception(str(exc))