bpo-6135: Fix subprocess.check_output doc to mention changes in 3.6 (GH-5564) (GH-5572)

Fixes the documentation for `subprocess.check_output()` not mentioning that the encoding and errors parameters were added in 3.6.
(cherry picked from commit fc1ce810f1da593648b4d19e7d582a235ec1dd37)

Co-authored-by: Brice Gros <brice-gros@users.noreply.github.com>
1 file changed