refactor(webrtc): remove example in favor of browser-webrtc example

We've moved away from having individual examples in crates in #3111. This one in `transports/webrtc` seems to have slipped through.

Pull-Request: #4531.

transports/webrtc/Cargo.toml

@@ -38,20 +38,10 @@ tokio = ["dep:tokio", "dep:tokio-util", "dep:webrtc", "if-watch/tokio"]
 pem = ["webrtc?/pem"]
 
 [dev-dependencies]
-anyhow = "1.0"
 env_logger = "0.10"
-hex-literal = "0.4"
-libp2p-swarm = { workspace = true, features = ["macros", "tokio"] }
-libp2p-ping = { workspace = true }
 tokio = { version = "1.32", features = ["full"] }
-unsigned-varint = { version = "0.7", features = ["asynchronous_codec"] }
-void = "1"
 quickcheck = "1.0.3"
 
 [[test]]
 name = "smoke"
 required-features = ["tokio"]
-
-[[example]]
-name = "listen_ping"
-required-features = ["tokio"]

transports/webrtc/src/tokio/certificate.rs

@@ -97,24 +97,18 @@ enum Kind {
     InvalidPEM(#[from] webrtc::Error),
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature = "pem"))]
 mod test {
-    #[cfg(feature = "pem")]
-    use anyhow::Result;
+    use super::*;
+    use rand::thread_rng;
 
-    #[cfg(feature = "pem")]
     #[test]
-    fn test_certificate_serialize_pem_and_from_pem() -> Result<()> {
-        use super::*;
-        use rand::thread_rng;
-
+    fn test_certificate_serialize_pem_and_from_pem() {
         let cert = Certificate::generate(&mut thread_rng()).unwrap();
 
         let pem = cert.serialize_pem();
-        let loaded_cert = Certificate::from_pem(&pem)?;
-
-        assert_eq!(loaded_cert, cert);
+        let loaded_cert = Certificate::from_pem(&pem).unwrap();
 
-        Ok(())
+        assert_eq!(loaded_cert, cert)
     }
 }