ci(build_latest.yml): Switch from Qt 6.9 to Qt 6.10

This also works around an issue where `aqtinstall` attempt was attempting
to download the non existing checksum associated with `qt6_693/qt6_693/Updates.xml`[^1].
Indeed, as of Sept 29th 2025, the file `qt6_693/qt6_693/Updates.xml.sha256`[^2] is not
available anymore.

[^1]: https://download.qt.io/online/qtsdkrepository/linux_x64/desktop/qt6_693/qt6_693/Updates.xml
[^2]: https://download.qt.io/online/qtsdkrepository/linux_x64/desktop/qt6_693/qt6_693/Updates.xml.sha256

Author: jcfr

.github/workflows/build_latest.yml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ['ubuntu', 'windows']
-        qt-version: [ '5.12.*', '5.15.*', '6.9.*' ]
+        qt-version: [ '5.12.*', '5.15.*', '6.10.*' ]
         python-version: [ '3.12' ]
     runs-on: ${{ matrix.os }}-latest
     steps: