QTextToSpeech: compile with QT_NO_CAST_FROM_BYTEARRAY


A QByteArray obtained from QString::toUtf8() is always NUL-terminated,
so the code was ok before, just running afoul of the opt-out macro.

Just make the .data() call explicit.

Amends 786e03db197f081c992aff401fb085867c550c2d (6.6).

Pick-to: 6.11 6.10 6.8
Change-Id: Iead0a27a9e2b13c45d15f71a32ebadd004ae6472
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
commit4069f29b8b7f397e4cf26594242817155f659260
parentc79dc7a0d24c9868370f79f41d641df06a538ce4
authorMarc Mutz <marc.mutz@qt.io>
committerMarc Mutz <marc.mutz@qt.io>
commit timeFri, 27 Mar 2026 14:45:23 +0100