As of gh-33806, the HttpComponents client request factory is forward
compatible with the 5.4+ versions of that library for configuring HTTP
request configuration.
This change would not tkae into account configuration set at the Spring
level because it would consider the default `RequestConfig` instance as
a custom one. This commit ensures that Spring sets its own configuration
if no custom configuration was set for all supported HttpComponents
generations.
Fixes gh-34851
6f11711e27