Allow to reset fd in `PipeWireSourceItem`
The dtor of the source stream object is called after Component.onDestruction in QML, so the file descriptor can be closed after a new PipeWireSourceItem creates, which causes the bug. CCBUG: 464597
The dtor of the source stream object is called after Component.onDestruction in QML, so the file descriptor can be closed after a new PipeWireSourceItem creates, which causes the bug. CCBUG: 464597
mentioned in commit e96ff18c