Description of problem:
Package qt6-qtwebengine fails to build from source in Fedora Rawhide.

Version-Release number of selected component (if applicable):
qt6-qtwebengine-6.5.1-2.fc39

Steps to Reproduce:
koji build --scratch f39 qt6-qtwebengine-6.5.1-2.fc39.src.rpm

Additional info:

The build log ends with:

FAILED: gen/chrome/browser/resources/components/components.ts 
/usr/bin/python3 ../../../../../src/3rdparty/chromium/tools/grit/preprocess_if_expr.py --in-folder ../../../../../src/3rdparty/chromium/chrome/browser/resources/components --out-folder gen/chrome/browser/resources/components --in-files components.ts -D DEVTOOLS_GRD_PATH=gen/third_party/devtools-frontend/src/front_end/devtools_resources -D SHARED_INTERMEDIATE_DIR=gen -D _google_chrome=false -D _google_chrome_for_testing=false -D chromeos_ash=false -D chromeos_lacros=false -D reven=false -D toolkit_views=false -D use_aura=true -D use_ozone=true -D use_titlecase=false -D scale_factors=2x -E root_gen_dir=gen -E root_src_dir=../../../../../src/3rdparty/chromium/ -E CHROMIUM_BUILD=chromium -t linux
Traceback (most recent call last):
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/redhat-linux-build/src/core/RelWithDebInfo/x86_64/../../../../../src/3rdparty/chromium/tools/grit/preprocess_if_expr.py", line 13, in <module>
    import grit.node.base
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/src/3rdparty/chromium/tools/grit/grit/node/base.py", line 21, in <module>
    from grit import util
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/src/3rdparty/chromium/tools/grit/grit/util.py", line 21, in <module>
    from six.moves import html_entities as entities
ModuleNotFoundError: No module named 'six.moves'


This issue can be solved by adding the following line in the %prep section of the soecfile:

sed "s;'six', ;;" -i src/3rdparty/chromium/tools/grit/grit/__init__.py


However, after fixing this the build instead fails with:

/usr/bin/python3 ../../../../../src/3rdparty/chromium/mojo/public/tools/mojom/mojom_parser.py --input-root ../../../../../src/3rdparty/chromium --input-root gen --output-root gen --mojom-file-list=__chrome_browser_ui_webui_internals_user_education_mojo_bindings__parser__builddir_build_BUILD_qtwebengine-everywhere-src-6.5.1_redhat-linux-build_src_core_target_toolchain_target__rule..rsp --check-imports gen/chrome/browser/ui/webui/internals/user_education/mojo_bindings.build_metadata --enable-feature is_posix --enable-feature is_linux --add-module-metadata webui_module_path=/chrome/browser/ui/webui/internals/user_education
Traceback (most recent call last):
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/redhat-linux-build/src/core/RelWithDebInfo/x86_64/../../../../../src/3rdparty/chromium/mojo/public/tools/mojom/mojom_parser.py", line 27, in <module>
    from mojom.generate import translate
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/src/3rdparty/chromium/mojo/public/tools/mojom/mojom/generate/translate.py", line 16, in <module>
    from mojom.generate import generator
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/src/3rdparty/chromium/mojo/public/tools/mojom/mojom/generate/generator.py", line 12, in <module>
    from mojom import fileutil
  File "/builddir/build/BUILD/qtwebengine-everywhere-src-6.5.1/src/3rdparty/chromium/mojo/public/tools/mojom/mojom/fileutil.py", line 6, in <module>
    import imp
ModuleNotFoundError: No module named 'imp'


The imp module was removed from Pythin 3.12. Several files in 3rdparty/chromium use it and must be updated-


Reproducible: Always