chore: remove unused webrtc patches (#16440)

Closes #16424

patches/common/webrtc/.patches.yaml

@@ -1,7 +0,0 @@
-repo: src/third_party/webrtc
-patches:
--
-  author: Nitish Sakhawalkar <[email protected]>
-  file: disable-warning-win.patch
-  description:
-    Disable windows warning

patches/common/webrtc/disable-warning-win.patch

@@ -1,16 +0,0 @@
-diff --git a/rtc_base/thread.cc b/rtc_base/thread.cc
-index 1bc0c0cd8..51208e4f0 100644
---- a/rtc_base/thread.cc
-+++ b/rtc_base/thread.cc
-@@ -23,7 +23,10 @@
- #include "rtc_base/stringutils.h"
- #include "rtc_base/timeutils.h"
- #include "rtc_base/trace_event.h"
--
-+#ifdef _WIN32
-+//Warning on windows because ThreadManager destructor never returns
-+#pragma warning(disable:4722)
-+#endif
- namespace rtc {
- 
- ThreadManager* ThreadManager::Instance() {