Bump version to 6.13.0


Change-Id: I966602c9eaea4d0185af3524e1195a6f0cbd8d10
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>
commitbd42687353c4443065471e5cbd06b6f8a080bdc0
parentec0004e1e6763058f063cb43578285eeb2cf8f6c
authorJani Heikkinen <jani.heikkinen@qt.io>
committerJani Heikkinen <jani.heikkinen@qt.io>
commit timeThu, 4 Jun 2026 19:26:01 +0000