Cleanup python version properties

Now that python 2 is fully removed, there's no need for
version-specific properties. Remove them.

Also remove usages of embedded_launcher: true, as that
is the new default value.

Bug: 399954452
Test: Presubmits
Change-Id: I7836bc5fe794096a27d5bcf9630f598b6bc41c8a
1 file changed
tree: 6d5adf9dbe496e77a94b4c337c02b764b94f5731
  1. net/
  2. tools/
  3. METADATA