Remove libevent tasks queue factory

which is now unused. Also remove libevent from DEPS and
generate_licenses.py

BUG=webrtc:42224654

Change-Id: I30aceaa304b4c6fb23e8485172f38bdaf18daf2f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/382581
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@meta.com>
Cr-Commit-Position: refs/heads/main@{#44216}
diff --git a/api/task_queue/default_task_queue_factory_libevent.cc b/api/task_queue/default_task_queue_factory_libevent.cc
deleted file mode 100644
index 89079f5..0000000
--- a/api/task_queue/default_task_queue_factory_libevent.cc
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- *  Copyright 2019 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-#include <memory>
-
-#include "api/field_trials_view.h"
-#include "api/task_queue/task_queue_factory.h"
-#include "rtc_base/task_queue_libevent.h"
-
-namespace webrtc {
-
-std::unique_ptr<TaskQueueFactory> CreateDefaultTaskQueueFactory(
-    const FieldTrialsView* field_trials) {
-  return CreateTaskQueueLibeventFactory();
-}
-
-}  // namespace webrtc
diff --git a/rtc_base/DEPS b/rtc_base/DEPS
index a936a22..9564ac9 100644
--- a/rtc_base/DEPS
+++ b/rtc_base/DEPS
@@ -2,7 +2,6 @@
   "+json",
   "+system_wrappers",
   "+third_party/jsoncpp",
-  "+third_party/libevent",
 ]
 
 specific_include_rules = {
diff --git a/tools_webrtc/libs/generate_licenses.py b/tools_webrtc/libs/generate_licenses.py
index eb49857..7e1d2e9 100755
--- a/tools_webrtc/libs/generate_licenses.py
+++ b/tools_webrtc/libs/generate_licenses.py
@@ -55,7 +55,6 @@
     'libaom': ['third_party/libaom/source/libaom/LICENSE'],
     'libc++': ['third_party/libc++/src/LICENSE.TXT'],
     'libc++abi': ['third_party/libc++abi/src/LICENSE.TXT'],
-    'libevent': ['third_party/libevent/LICENSE'],
     'libjpeg_turbo': ['third_party/libjpeg_turbo/LICENSE.md'],
     'libsrtp': ['third_party/libsrtp/LICENSE'],
     'libunwind': ['third_party/libunwind/src/LICENSE.TXT'],