Fix expected log output

This appears to have changed somewhere between golang 1.23 rc1 and
golang 1.23.2

Signed-off-by: Michel Lind <salimma@fedoraproject.org>

example_test.go

@@ -54,5 +54,5 @@ func ExampleNewWithOptions() {
 	log := stdr.NewWithOptions(newStdLogger(0), stdr.Options{LogCaller: stdr.All})
 	log.Info("with LogCaller=All")
 	// Output:
-	// "caller"={"file":"example_test.go","line":55} "level"=0 "msg"="with LogCaller=All"
+	// "caller"={"file"="example_test.go" "line"=55} "level"=0 "msg"="with LogCaller=All"
 }