tools/setup: Delete static/generated/bots before repopulating.
tools/setup: Delete static/generated/bots before repopulating.

tools/setup/generate_zulip_bots_static_files now starts off by
deleting static/generated/bots/ (if it hasn't been removed already)
so that outdated static files from older versions of the zulip_bots
package don't supress errors in the main repo that would otherwise
break.

For more info, see #7542

Fixes: #7542.

mahim97/zulip,showell/zulip,dhcrzf/zulip,rishig/zulip,timabbott/zulip,rishig/zulip,synicalsyntax/zulip,andersk/zulip,jackrzhang/zulip,kou/zulip,rishig/zulip,andersk/zulip,zulip/zulip,dhcrzf/zulip,showell/zulip,jackrzhang/zulip,shubhamdhama/zulip,tommyip/zulip,jackrzhang/zulip,shubhamdhama/zulip,tommyip/zulip,punchagan/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,kou/zulip,hackerkid/zulip,zulip/zulip,eeshangarg/zulip,brainwane/zulip,rht/zulip,dhcrzf/zulip,synicalsyntax/zulip,zulip/zulip,timabbott/zulip,shubhamdhama/zulip,hackerkid/zulip,brainwane/zulip,punchagan/zulip,timabbott/zulip,eeshangarg/zulip,tommyip/zulip,rht/zulip,punchagan/zulip,jackrzhang/zulip,brainwane/zulip,showell/zulip,tommyip/zulip,hackerkid/zulip,rht/zulip,rht/zulip,rishig/zulip,dhcrzf/zulip,synicalsyntax/zulip,jackrzhang/zulip,mahim97/zulip,brainwane/zulip,mahim97/zulip,rishig/zulip,eeshangarg/zulip,eeshangarg/zulip,andersk/zulip,rht/zulip,zulip/zulip,showell/zulip,zulip/zulip,rht/zulip,shubhamdhama/zulip,kou/zulip,tommyip/zulip,punchagan/zulip,showell/zulip,kou/zulip,mahim97/zulip,tommyip/zulip,andersk/zulip,synicalsyntax/zulip,shubhamdhama/zulip,timabbott/zulip,andersk/zulip,jackrzhang/zulip,mahim97/zulip,hackerkid/zulip,dhcrzf/zulip,timabbott/zulip,rht/zulip,showell/zulip,tommyip/zulip,shubhamdhama/zulip,brainwane/zulip,brainwane/zulip,showell/zulip,rishig/zulip,synicalsyntax/zulip,hackerkid/zulip,eeshangarg/zulip,shubhamdhama/zulip,synicalsyntax/zulip,punchagan/zulip,brainwane/zulip,rishig/zulip,hackerkid/zulip,mahim97/zulip,hackerkid/zulip,andersk/zulip,jackrzhang/zulip,dhcrzf/zulip,andersk/zulip,kou/zulip,punchagan/zulip,dhcrzf/zulip,zulip/zulip,synicalsyntax/zulip,eeshangarg/zulip,punchagan/zulip,kou/zulip,timabbott/zulip,timabbott/zulip