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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