[ubports/focal] Merge version 5.15.19+dfsg-1 from Debian experimental

While we're at it, backport !41 (merged) to 20.04 branch.

qtwebengine-opensource-src (5.15.19+ubports-0ubports1) focal; urgency=medium

  * Merge version 5.15.19+dfsg-1 from Debian experimental.
  * d/ubports.source_location: update for 5.15.9+ubports
  * d/p/u/0007-hybris-omx.patch:
    - move frame creation to the main sequence
    - set GL texture as "cleared" at the earliest

 -- Ratchanan Srirattanamet <ratchanan@ubports.com>  Sat, 19 Jul 2025 16:43:22 +0700

qtwebengine-opensource-src (5.15.19+dfsg-1) experimental; urgency=medium

  * New upstream release.
  * Update SUBMODULE_COMMIT for the new release.
  * Drop python3.12-*.patch, no longer needed.
  * Refresh and rebase other patches.
  * Bump ABI version to qtwebengine-abi-5-15-19.
  * Build against Qt 5.15.17.
  * Update debian/libqt5webenginecore5.symbols from buildds’ logs.
  * Remove Qt_5.x symbols from the symbols files.
  * Make debian/scripts/update-copyright work with the new version.
  * Update debian/copyright.
  * Bump Standards-Version to 4.7.2, no changes needed.

 -- Dmitry Shachnev <mitya57@debian.org>  Wed, 09 Jul 2025 11:25:22 +0300