Bump version to 6.13.0


Change-Id: I83c91c1d79674710a65271d1d051b3408e552f51
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>
commit0b2798a3358b15690e0d60e54a247e3f45dbe788
parenta101c580de6f192904effefe3ad1dee6cf0a85f5
authorJani Heikkinen <jani.heikkinen@qt.io>
committerJani Heikkinen <jani.heikkinen@qt.io>
commit timeFri, 19 Jun 2026 03:34:43 +0000