FIX: Use sessionKeysFile for Zot OIDC session encryption

- Change from hashKeyFile/blockKeyFile inside sessionDriver to
  sessionKeysFile at auth config level
- Update ExternalSecret to generate session-keys.json with both
  hashKey and encryptKey in correct JSON format
- Fix securecookie validation error during OIDC callback

zot/helm-values.yaml

@@ -100,11 +100,8 @@ persistence:
     type: secret
     name: zot-session-keys
     globalMounts:
-    - path: /etc/zot/session-hashkey
-      subPath: hashKey
-      readOnly: true
-    - path: /etc/zot/session-blockkey
-      subPath: blockKey
+    - path: /etc/zot/session-keys.json
+      subPath: session-keys.json
       readOnly: true
 
 configMaps:
@@ -146,12 +143,11 @@ configMaps:
                   }
                 }
               },
+              "sessionKeysFile": "/etc/zot/session-keys.json",
               "sessionDriver": {
                 "name": "redis",
                 "url": "redis://authelia-redis-master.authelia.svc.cluster.local:6379",
-                "keyprefix": "zot",
-                "hashKeyFile": "/etc/zot/session-hashkey",
-                "blockKeyFile": "/etc/zot/session-blockkey"
+                "keyprefix": "zot"
               }
             }
           },