push_notifs: Handle more requests Exceptions in send_to_push_bouncer.
push_notifs: Handle more requests Exceptions in send_to_push_bouncer.

Closes #13294.

showell/zulip,showell/zulip,timabbott/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,synicalsyntax/zulip,andersk/zulip,shubhamdhama/zulip,timabbott/zulip,shubhamdhama/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,synicalsyntax/zulip,andersk/zulip,punchagan/zulip,timabbott/zulip,rht/zulip,punchagan/zulip,andersk/zulip,hackerkid/zulip,zulip/zulip,kou/zulip,showell/zulip,showell/zulip,showell/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,shubhamdhama/zulip,brainwane/zulip,rht/zulip,synicalsyntax/zulip,zulip/zulip,brainwane/zulip,zulip/zulip,timabbott/zulip,synicalsyntax/zulip,timabbott/zulip,timabbott/zulip,hackerkid/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,brainwane/zulip,eeshangarg/zulip,hackerkid/zulip,punchagan/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,zulip/zulip,shubhamdhama/zulip,punchagan/zulip,synicalsyntax/zulip,hackerkid/zulip,showell/zulip,kou/zulip,shubhamdhama/zulip,andersk/zulip,rht/zulip,zulip/zulip,shubhamdhama/zulip,synicalsyntax/zulip,kou/zulip,rht/zulip,punchagan/zulip,brainwane/zulip,synicalsyntax/zulip,timabbott/zulip,hackerkid/zulip,punchagan/zulip,andersk/zulip,shubhamdhama/zulip,brainwane/zulip,punchagan/zulip,andersk/zulip,showell/zulip,kou/zulip,eeshangarg/zulip