Important: Please read the migration guide.

Bug fixes:

• [middleware, authentication] Remove map lookup making the basic auth notFoundSecret empty (#12960 @rtribotte)
• [middleware, authentication] Fix trustForwardHeader on forward auth middleware (#12994 @juliens)
• [middleware, authentication] Cleanup and make ForwardAuth logs consistent (#13013 @kevinpollet)
• [middleware] Remove untrusted X headers with underscores (#12961 @rtribotte)
• [middleware] Sanitize the request URL after stripping the prefix (#12990 @kevinpollet)
• [k8s/crd, k8s] Honor allowCrossNamespace with chain middleware CRD (#12976 @rtribotte)