docs: Remove legacy Python2/3 compatibility code.
docs: Remove legacy Python2/3 compatibility code.

rishig/zulip,eeshangarg/zulip,timabbott/zulip,zulip/zulip,synicalsyntax/zulip,hackerkid/zulip,jackrzhang/zulip,andersk/zulip,rishig/zulip,kou/zulip,amanharitsh123/zulip,dhcrzf/zulip,tommyip/zulip,shubhamdhama/zulip,rht/zulip,eeshangarg/zulip,punchagan/zulip,punchagan/zulip,jackrzhang/zulip,kou/zulip,punchagan/zulip,timabbott/zulip,shubhamdhama/zulip,Galexrt/zulip,hackerkid/zulip,Galexrt/zulip,andersk/zulip,verma-varsha/zulip,hackerkid/zulip,rht/zulip,amanharitsh123/zulip,jackrzhang/zulip,zulip/zulip,shubhamdhama/zulip,eeshangarg/zulip,punchagan/zulip,showell/zulip,brainwane/zulip,rht/zulip,rishig/zulip,tommyip/zulip,brainwane/zulip,verma-varsha/zulip,showell/zulip,andersk/zulip,mahim97/zulip,dhcrzf/zulip,brockwhittaker/zulip,dhcrzf/zulip,showell/zulip,kou/zulip,verma-varsha/zulip,Galexrt/zulip,rht/zulip,andersk/zulip,brainwane/zulip,eeshangarg/zulip,shubhamdhama/zulip,zulip/zulip,shubhamdhama/zulip,zulip/zulip,amanharitsh123/zulip,jackrzhang/zulip,eeshangarg/zulip,brockwhittaker/zulip,amanharitsh123/zulip,tommyip/zulip,mahim97/zulip,showell/zulip,rishig/zulip,brockwhittaker/zulip,rishig/zulip,mahim97/zulip,brockwhittaker/zulip,punchagan/zulip,mahim97/zulip,rishig/zulip,hackerkid/zulip,brainwane/zulip,punchagan/zulip,amanharitsh123/zulip,verma-varsha/zulip,zulip/zulip,tommyip/zulip,dhcrzf/zulip,punchagan/zulip,hackerkid/zulip,verma-varsha/zulip,zulip/zulip,verma-varsha/zulip,synicalsyntax/zulip,Galexrt/zulip,kou/zulip,synicalsyntax/zulip,timabbott/zulip,dhcrzf/zulip,rht/zulip,hackerkid/zulip,rht/zulip,synicalsyntax/zulip,kou/zulip,timabbott/zulip,tommyip/zulip,andersk/zulip,timabbott/zulip,jackrzhang/zulip,showell/zulip,rishig/zulip,tommyip/zulip,hackerkid/zulip,brainwane/zulip,timabbott/zulip,brockwhittaker/zulip,synicalsyntax/zulip,mahim97/zulip,eeshangarg/zulip,Galexrt/zulip,amanharitsh123/zulip,eeshangarg/zulip,zulip/zulip,jackrzhang/zulip,mahim97/zulip,synicalsyntax/zulip,dhcrzf/zulip,tommyip/zulip,andersk/zulip,showell/zulip,showell/zulip,kou/zulip,andersk/zulip,synicalsyntax/zulip,brockwhittaker/zulip,shubhamdhama/zulip,Galexrt/zulip,timabbott/zulip,brainwane/zulip,brainwane/zulip,rht/zulip,jackrzhang/zulip,kou/zulip,dhcrzf/zulip,shubhamdhama/zulip,Galexrt/zulip