dev-python/typed-ast: Remove python 3.9

Python 3.9 is not yet supported in Chrome OS.

Error message:
Invalid implementation in PYTHON_COMPAT: python3_9

BUG=b:162009542
TEST=sudo emerge mypy

Change-Id: I460594f8787c6eaaf675ff990a4d0b5a4521b7d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2316392
Tested-by: Tom Hughes <tomhughes@chromium.org>
Auto-Submit: Tom Hughes <tomhughes@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Tom Hughes <tomhughes@chromium.org>
1 file changed