h3: silence compiler warnings

Reviewed-by: Daniel Stenberg
Fixes #10485
Closes #10486

lib/vquic/curl_ngtcp2.c

@@ -1282,6 +1282,8 @@ static ssize_t recv_closed_stream(struct Curl_cfilter *cf,
   struct HTTP *stream = data->req.p.http;
   ssize_t nread = -1;
 
+  (void)cf;
+
   if(stream->reset) {
     failf(data,
           "HTTP/3 stream %" PRId64 " reset by server", stream->stream3_id);
@@ -1332,6 +1334,8 @@ static ssize_t cf_ngtcp2_recv(struct Curl_cfilter *cf, struct Curl_easy *data,
   ssize_t nread = -1;
   struct cf_call_data save;
 
+  (void)ctx;
+
   CF_DATA_SAVE(save, cf, data);
   DEBUGASSERT(cf->connected);
   DEBUGASSERT(ctx);

lib/vquic/vquic.c

@@ -327,6 +327,7 @@ CURLcode Curl_cf_quic_create(struct Curl_cfilter **pcf,
                              const struct Curl_addrinfo *ai,
                              int transport)
 {
+  (void)transport;
   DEBUGASSERT(transport == TRNSPRT_QUIC);
 #ifdef USE_NGTCP2
   return Curl_cf_ngtcp2_create(pcf, data, conn, ai);