The min SCons version had to be bumped as SCons 3.0 before 3.0.3 seems
broken (see #92043), and there's little gain from supporting 3.0.3-3.0.5.
3.1.2 is also the first version to avoid ambiguities between Python 2
and Python 3 usage, so we finally use it as the minimum baseline.
Also test against Python 3.6 which is also our minimum supported version.
This should help prevent regressions whenever we modernize the build scripts.
actions/cache@v3
actions/checkout@v3
actions/upload-artifact@v3
actions/setup-dotnet@v2
actions/setup-java@v3
actions/setup-python@v4
mymindstorm/setup-emsdk@v11
Also reset cache keys as we're going to cleanup all caches.
