Drop support for and remove references to EOL Python 3.6 (#11683)

* remove reference in comments to python3.6

* upgrade tox python env in script

* bump python version in example for completeness

* upgrade python version requirement in setup doc

* upgrade necessary python version in __init__.py

* upgrade python version in setup.py

* newsfragment

* drops refs to bionic and replace with focal

* bump refs to postgres 9.6 to 10

* fix hanging ci

* try installing tzdata first

* revert change made in b979f336

* ignore new random mypy error while debugging other error

* fix lint error for temporary workaround

* revert change to install list

* try passing env var

* export debian frontend var?

* move line and add comment

* bump pillow dependency

* bump lxml depenency

* install libjpeg-dev for pillow

* bump automat version to one compatible with py3.8

* add libwebp for pillow

* bump twisted trunk python version

* change suffix of newsfragment

* remove redundant python 3.7 checks

* lint

1 files changed, 1 insertions, 2 deletions

diff --git a/tox.ini b/tox.ini
index 2ffca14b22..32679e9106 100644
--- a/tox.ini
+++ b/tox.ini
@@ -117,8 +117,7 @@ usedevelop=true
 skip_install = true
 usedevelop = false
 deps =
-    # Old automat version for Twisted
-    Automat == 0.3.0
+    Automat == 0.8.0
     lxml
     {[base]deps}