Disable passing on authorization header by default

In https://github.com/adobe/aem-project-archetype/blob/183706c16758fc02a8becc16d2dc8a5b55e7ef46/src/main/archetype/dispatcher.cloud/src/conf.dispatcher.d/clientheaders/default_clientheaders.any#L43 the `Authorization` header is forwarded to AEM. That can be abused with certain endpoints to do brute-force credential attacks on the Basic Auth Handler (compare with https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/disable-basic-authentication/m-p/359084/highlight/true#M48638). Therefore I would argue that by default those headers should not be forwarded to the backend. The default AEM authorization relies on cookies only (and not the authorization header which is only used for OAuth and Basic Auth). As that is an immutable file and customers can only add additional headers on top, this base configuration makes it impossible to strip Authorization headers (except with workarounds like using `mod_headers`)

Read src/main/archetype/dispatcher.cloud/src/conf.dispatcher.d/clientheaders/default_clientheaders.any at line 43 and review how the default client-header configuration forwards Authorization to AEM. Confirm the default configuration no longer forwards that header while preserving the stated cookie-based authorization behavior.

Written by the indexing model from the issue text.