chore: improve test setup

.dockerignore

@@ -0,0 +1 @@
+tests

tests/docker/ionscale/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.20-buster as builder
+FROM golang:1.21-bullseye as builder
 
 WORKDIR /app
 

tests/sc/scenario.go

@@ -105,8 +105,6 @@ func (s *scenario) NewTailscaleNode(hostname string) TailscaleNode {
 }
 
 func Run(t *testing.T, f func(s Scenario)) {
-	t.Parallel()
-
 	if testing.Short() {
 		t.Skip("skipped due to -short flag")
 	}