Require Go 1.20, update dependencies.

Recent versions of Pion have removed support for 1.19.

go.mod

@@ -1,6 +1,6 @@
 module github.com/jech/galene
 
-go 1.19
+go 1.20
 
 require (
 	github.com/at-wat/ebml-go v0.17.1
@@ -8,32 +8,32 @@ require (
 	github.com/gorilla/websocket v1.5.0
 	github.com/jech/cert v0.0.0-20240301122532-f491cf43a77d
 	github.com/jech/samplebuilder v0.0.0-20221109182433-6cbba09fc1c9
-	github.com/pion/ice/v2 v2.3.31
+	github.com/pion/ice/v2 v2.3.34
 	github.com/pion/rtcp v1.2.14
-	github.com/pion/rtp v1.8.7
+	github.com/pion/rtp v1.8.9
 	github.com/pion/sdp/v3 v3.0.9
 	github.com/pion/turn/v2 v2.1.6
-	github.com/pion/webrtc/v3 v3.2.50
-	golang.org/x/crypto v0.25.0
-	golang.org/x/sys v0.22.0
+	github.com/pion/webrtc/v3 v3.3.1
+	golang.org/x/crypto v0.27.0
+	golang.org/x/sys v0.25.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/uuid v1.6.0 // indirect
-	github.com/pion/datachannel v1.5.8 // indirect
+	github.com/pion/datachannel v1.5.9 // indirect
 	github.com/pion/dtls/v2 v2.2.12 // indirect
-	github.com/pion/interceptor v0.1.29 // indirect
+	github.com/pion/interceptor v0.1.30 // indirect
 	github.com/pion/logging v0.2.2 // indirect
 	github.com/pion/mdns v0.0.12 // indirect
 	github.com/pion/randutil v0.1.0 // indirect
-	github.com/pion/sctp v1.8.19 // indirect
+	github.com/pion/sctp v1.8.33 // indirect
 	github.com/pion/srtp/v2 v2.0.20 // indirect
 	github.com/pion/stun v0.6.1 // indirect
-	github.com/pion/transport/v2 v2.2.9 // indirect
+	github.com/pion/transport/v2 v2.2.10 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.9.0 // indirect
-	github.com/wlynxg/anet v0.0.3 // indirect
-	golang.org/x/net v0.27.0 // indirect
+	github.com/wlynxg/anet v0.0.4 // indirect
+	golang.org/x/net v0.29.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )