Restore old namespace reconciliation behaviour

The xmlDOMWrapReconcileNamespaces method we used to fix the namespace
corruption issues in 8.1.21/8.2.8 caused regressions.
Primarily,

Restore old namespace reconciliation behaviour

The xmlDOMWrapReconcileNamespaces method we used to fix the namespace
corruption issues in 8.1.21/8.2.8 caused regressions.
Primarily, there is a similar corruption that the xmlReconciliateNs method
used to have in which a namespace is suddenly shifted
(SAML-Toolkits/php-saml#562) and the side-effect of removing redundant
namespaces causes problems when a specific serialization is required.

Closes GH-12308.

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