[3.11] gh-111881: Use lazy import in test.support (#111885) (#111890) (#111902)

[3.12] gh-111881: Use lazy import in test.support (#111885) (#111890)

gh-111881: Use lazy import in test.support (#111885)

* Import lazily getpass in test.support

Backport to 3.11: test.support.os_helper is unchanged.

(cherry picked from commit 0372e3b02a7e3dc1c564dba94dcd817c5472b04f)
(cherry picked from commit e983ca859de279682631dbb13b959f14a7d89a7b)