Unskip the proxy URL tests. (#4321)

The original issue appears to have been fixed.

Author: cmacknz

testing/integration/proxy_url_test.go

@@ -99,7 +99,6 @@ func TestProxyURL_EnrollProxyAndNoProxyInThePolicy(t *testing.T) {
 		Local: false,
 		Sudo:  true,
 	})
-	t.Skip("Flaky test: https://github.com/elastic/elastic-agent/issues/3154")
 
 	p := SetupTest(t)
 	t.Cleanup(func() {
@@ -147,7 +146,6 @@ func TestProxyURL_EnrollProxyAndEmptyProxyInThePolicy(t *testing.T) {
 		Local: false,
 		Sudo:  true,
 	})
-	t.Skip("Flaky test: https://github.com/elastic/elastic-agent/issues/3154")
 
 	p := SetupTest(t)
 	t.Cleanup(func() {
@@ -197,7 +195,6 @@ func TestProxyURL_ProxyInThePolicyTakesPrecedence(t *testing.T) {
 		Local: false,
 		Sudo:  true,
 	})
-	t.Skip("Flaky test: https://github.com/elastic/elastic-agent/issues/3154")
 
 	p := SetupTest(t)
 	t.Cleanup(func() {
@@ -261,7 +258,6 @@ func TestProxyURL_NoEnrollProxyAndProxyInThePolicy(t *testing.T) {
 		Local: false,
 		Sudo:  true,
 	})
-	t.Skip("Flaky test: https://github.com/elastic/elastic-agent/issues/3154")
 
 	p := SetupTest(t)
 	t.Cleanup(func() {
@@ -329,7 +325,6 @@ func TestProxyURL_RemoveProxyFromThePolicy(t *testing.T) {
 		Local: false,
 		Sudo:  true,
 	})
-	t.Skip("Flaky test: https://github.com/elastic/elastic-agent/issues/3154")
 
 	p := SetupTest(t)
 	t.Cleanup(func() {