error-bot: Remove ERROR_BOT support.

This isn't sufficiently useful to keep the added complexity.  Users
should use the email error reporting, or set up Sentry error
reporting.

zerver/lib/error_notify.py

@@ -1,16 +1,15 @@
 # System documented in https://zulip.readthedocs.io/en/latest/subsystems/logging.html
 from collections import defaultdict
-from typing import Any, Dict, Literal
+from typing import Any, Dict
 
-from django.conf import settings
 from django.core.mail import mail_admins
 
-from zerver.actions.message_send import internal_send_stream_message
 from zerver.filters import clean_data_from_query_parameters
-from zerver.models import get_realm, get_stream, get_system_bot
 
 
-def send_error(channel: Literal["email", "zulip"], report: Dict[str, Any]) -> None:
+def do_report_error(report: Dict[str, Any]) -> None:
+    report = defaultdict(lambda: None, report)
+
     topic = "{node}: {message}".format(**report).replace("\n", "\\n").replace("\r", "\\r")
 
     logger_str = "Logger {logger_name}, from module {log_module} line {log_lineno}:".format(
@@ -45,8 +44,7 @@ Request info:
     else:
         request_repr = "Request info: none\n"
 
-    if channel == "email":
-        message = f"""\
+    message = f"""\
 {logger_str}
 Error generated by {user_info}
 
@@ -56,33 +54,4 @@ Error generated by {user_info}
 
 {request_repr}"""
 
-        mail_admins(topic, message, fail_silently=True)
-    else:
-        assert settings.ERROR_BOT is not None
-        message = f"""{logger_str}
-Error generated by {user_info}
-
-~~~~ pytb
-{report['stack_trace']}
-
-~~~~
-{deployment}
-{request_repr}"""
-
-        error_bot_realm = get_realm(settings.STAFF_SUBDOMAIN)
-        error_bot = get_system_bot(settings.ERROR_BOT, error_bot_realm.id)
-        errors_stream = get_stream("errors", error_bot_realm)
-
-        internal_send_stream_message(
-            error_bot,
-            errors_stream,
-            topic,
-            message,
-        )
-
-
-def do_report_error(report: Dict[str, Any]) -> None:
-    report = defaultdict(lambda: None, report)
-    send_error("email", report)
-    if settings.ERROR_BOT:
-        send_error("zulip", report)
+    mail_admins(topic, message, fail_silently=True)