chore: avoid unnecessary byte/string conversion calls (#21854)

* chore: avoid unnecessary conversion calls

* add changelog entry

---------

Co-authored-by: Violet Hynes <violet.hynes@hashicorp.com>

plugins/database/redshift/redshift_test.go

@@ -161,7 +161,7 @@ func TestRedshift_NewUser(t *testing.T) {
 		}
 
 		usernameRegex := regexp.MustCompile("^v-test-test-[a-zA-Z0-9]{20}-[0-9]{10}$")
-		if !usernameRegex.Match([]byte(username)) {
+		if !usernameRegex.MatchString(username) {
 			t.Fatalf("Expected username %q to match regex %q", username, usernameRegex.String())
 		}
 	}