Fix logoutRequestRepository not set on Saml2RelyingPartyInitiatedLogoutSuccessHandler

[sawprogramming]

When using XML to configure Spring Security for SAML, the logoutRequestRepository is not set on the Saml2RelyingPartyInitiatedLogoutSuccessHandler like it should be. See how it is properly set using the Java DSL (:

private Saml2RelyingPartyInitiatedLogoutFilter createRelyingPartyLogoutFilter(
		RelyingPartyRegistrationRepository registrations) {
	LogoutHandler[] logoutHandlers = this.logoutHandlers.toArray(new LogoutHandler[0]);
	Saml2RelyingPartyInitiatedLogoutSuccessHandler logoutRequestSuccessHandler = createSaml2LogoutRequestSuccessHandler(
			registrations);
	logoutRequestSuccessHandler.setLogoutRequestRepository(this.logoutRequestConfigurer.logoutRequestRepository);
	Saml2RelyingPartyInitiatedLogoutFilter logoutFilter = new Saml2RelyingPartyInitiatedLogoutFilter(
			logoutRequestSuccessHandler, logoutHandlers);
	logoutFilter.setLogoutRequestMatcher(createLogoutMatcher());
	return postProcess(logoutFilter);
}

Without this fix, SAML configurations that use custom logout request repositories do not work for RP-initiated logouts.

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[jzheaux]

Thank you, @sawprogramming, for catching this. This seems to be a bug and so I'd like to apply it first to 6.2.x. Are you able to rebase your branch with 6.2.x?

Also, are you able to add a test to Saml2LogoutBeanDefinitionParserTests, like this one in the related Java Config commit?

I can also help with either or both, so please feel free to ask.

Finally, would you also change the commit title to resemble the one from that commit? You might do:

Set LogoutRequestRepository on Saml2 LogoutSuccessHandler in XML

Closes gh-16093