bump go version

go.mod

@@ -1,16 +1,28 @@
 module beryju.io/oidc-test-client
 
-go 1.16
+go 1.20
 
 require (
 	github.com/cli/oauth v1.0.1
 	github.com/coreos/go-oidc v2.2.1+incompatible
 	github.com/gorilla/securecookie v1.1.1
 	github.com/gorilla/sessions v1.2.1
-	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 // indirect
 	github.com/sirupsen/logrus v1.9.3
 	github.com/spf13/cobra v1.7.0
 	golang.org/x/net v0.15.0
 	golang.org/x/oauth2 v0.12.0
+)
+
+require (
+	github.com/cli/browser v1.0.0 // indirect
+	github.com/cli/safeexec v1.0.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/crypto v0.13.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
 	gopkg.in/square/go-jose.v2 v2.5.1 // indirect
 )