Emscripten 4.0.7 requires Python +3.8, OpenSUSE does have Python 3.11
but its path is only set to PYTHON3_EXECUTABLE envvar defined in
08-pythondev.sh.
OpenSUSE 15.6 comes with Python 3.6.15 which the previous emscripten
3.1.70 used.
Pick-to: 6.10
Change-Id: Ied63ace32b7fb252d124ad447bc56dba353ff403
Reviewed-by: Lorn Potter <lorn.potter@qt.io>