Bug - SimpleSelect - An open menu still accepts selection after disabling #12711

Describe the problem

SimpleSelect can still change its selection after its toggle becomes disabled.

How do you reproduce the problem?

1. Open a SimpleSelect with Apple selected.
2. Set isDisabled to true while the menu is still open.
3. Click Orange. Orange becomes selected and onSelect runs.

Expected behavior

Apple stays selected and onSelect does not run.

Screenshots

Watch the browser reproduction.

What is your environment?

Chromium on macOS, with the official PatternFly stylesheet. Reproduced on @patternfly/react-templates 6.7.0 and current main.

Any other information?

I am preparing a regression test and a small fix for this issue.