chore(testutil): add testutil.GetRandomName that does not return duplicates (#14020)

Fixes #13910

Adds testutil.GetRandomName that replaces namesgenerator.GetRandomName but instead appends a monotonically increasing integer instead of a number between 1 and 10.

testutil/names.go

@@ -0,0 +1,23 @@
+package testutil
+
+import (
+	"strconv"
+	"sync/atomic"
+	"testing"
+
+	"github.com/moby/moby/pkg/namesgenerator"
+)
+
+var n atomic.Int64
+
+// GetRandomName returns a random name using moby/pkg/namesgenerator.
+// namesgenerator.GetRandomName exposes a retry parameter that appends
+// a pseudo-random number between 1 and 10 to its return value.
+// While this reduces the probability of collisions, it does not negate them.
+// This function calls namesgenerator.GetRandomName without the retry
+// parameter and instead increments a monotonically increasing integer
+// to the return value.
+func GetRandomName(t testing.TB) string {
+	t.Helper()
+	return namesgenerator.GetRandomName(0) + strconv.FormatInt(n.Add(1), 10)
+}