Add security considerations page


Document the potential security issues that were identified for
QSerialPort and suggest ways to protect against them.

Fixes: QTBUG-148859
Pick-to: 6.12
Change-Id: I2d346bc6d7ac969cc8d070e3177c2325951485d9
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
commitbd98dcbc9bc6aeb64117c0bb298645032d9a5901
parentb031547406b89cd437ce2907a4a4a2b0b62b005d
authorIvan Solovev <ivan.solovev@qt.io>
committerIvan Solovev <ivan.solovev@qt.io>
commit timeMon, 21 Sep 2026 15:55:06 +0000