auth-server: bump go to 1.20

sechmann · sechmann · commit feaf62a9f917 · 2023-02-20T11:52:01.000+01:00
diff --git a/cmd/auth-server/go.mod b/cmd/auth-server/go.mod
@@ -1,6 +1,6 @@
 module github.com/nais/device/cmd/auth-server
 
-go 1.18
+go 1.20
 
 require (
 	github.com/kelseyhightower/envconfig v1.4.0
