Delete stale TODO about GFD fuzzing

GenericFrameDescriptor fuzzing is covered by RtpPacketFuzzer:
https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/test/fuzzers/rtp_packet_fuzzer.cc;l=140;drc=ef90964b830f8fc6f0c94c3f3a1b16687a345638

No-Try: true
Bug: webrtc:10198
Change-Id: I677f8452a9aefa11a6d66c382b14230d71622c04
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/290728
Reviewed-by: Emil Lundmark <lndmrk@webrtc.org>
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Emil Lundmark <lndmrk@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39055}
diff --git a/modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension_unittest.cc b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension_unittest.cc
index d7f8e1e..7c27326 100644
--- a/modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension_unittest.cc
@@ -21,8 +21,6 @@
 
 constexpr uint8_t kDeprecatedFlags = 0x30;
 
-// TODO(danilchap): Add fuzzer to test for various invalid inputs.
-
 TEST(RtpGenericFrameDescriptorExtensionTest,
      ParseFirstPacketOfIndependenSubFrame) {
   const int kTemporalLayer = 5;