Delete unimplemented methods from the NetEq interface.

Bug: None
Change-Id: I51949a096c445813acc6649676e32c575732ef40
Reviewed-on: https://webrtc-review.googlesource.com/95643
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24469}

modules/audio_coding/neteq/neteq_impl.h

@@ -157,8 +157,6 @@ class NetEqImpl : public webrtc::NetEq {
 
   bool SetMaximumDelay(int delay_ms) override;
 
-  int SetTargetDelay() override;
-
   int TargetDelayMs() const override;
 
   int CurrentDelayMs() const override;
@@ -194,10 +192,6 @@ class NetEqImpl : public webrtc::NetEq {
   absl::optional<SdpAudioFormat> GetDecoderFormat(
       int payload_type) const override;
 
-  int SetTargetNumberOfChannels() override;
-
-  int SetTargetSampleRate() override;
-
   // Flushes both the packet buffer and the sync buffer.
   void FlushBuffers() override;