fix(quic,tls,webrtc): pin pre-release version

If pre-releases aren't pinned, new ones can introduce breaking changes and be automatically fetched by cargo.

Pull-Request: #3538.

Cargo.toml

@@ -118,10 +118,10 @@ pin-project = "1.0.0"
 libp2p-deflate = { version = "0.39.0", path = "transports/deflate", optional = true }
 libp2p-dns = { version = "0.39.0", path = "transports/dns", optional = true }
 libp2p-mdns = { version = "0.43.0", path = "protocols/mdns", optional = true }
-libp2p-quic = { version = "0.7.0-alpha.2", path = "transports/quic", optional = true }
+libp2p-quic = { version = "=0.7.0-alpha.2", path = "transports/quic", optional = true }
 libp2p-tcp = { version = "0.39.0", path = "transports/tcp", optional = true }
-libp2p-tls = { version = "0.1.0-alpha.2", path = "transports/tls", optional = true }
-libp2p-webrtc = { version = "0.4.0-alpha.2", path = "transports/webrtc", optional = true }
+libp2p-tls = { version = "=0.1.0-alpha.2", path = "transports/tls", optional = true }
+libp2p-webrtc = { version = "=0.4.0-alpha.2", path = "transports/webrtc", optional = true }
 libp2p-websocket = { version = "0.41.0", path = "transports/websocket", optional = true }
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]