Fix race condition in tests accessing global variables in parallel

pkg/middlewares/observability/semconv_test.go

@@ -52,8 +52,6 @@ func TestSemConvServerMetrics(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			t.Parallel()
-
 			var cfg otypes.OTLP
 			(&cfg).SetDefaults()
 			cfg.AddRoutersLabels = true

pkg/proxy/httputil/observability_test.go

@@ -57,8 +57,6 @@ func TestObservabilityRoundTripper_metrics(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			t.Parallel()
-
 			var cfg otypes.OTLP
 			(&cfg).SetDefaults()
 			cfg.AddRoutersLabels = true