Update Azure secrets docs + deprecation

changelog/25637.txt

@@ -0,0 +1,3 @@
+```release-note:deprecation
+secrets/azure: Deprecate field "password_policy" as we are not able to set it anymore with the new MS Graph API.
+```

website/content/api-docs/secret/azure.mdx

@@ -34,8 +34,6 @@ service principals. Environment variables will override any parameters set in th
   provided with the AZURE_CLIENT_SECRET environment variable. See [authentication](/vault/docs/secrets/azure#authentication) for more details.
 - `environment` (`string:""`) - The Azure environment. This value can also be provided with the AZURE_ENVIRONMENT
   environment variable. If not specified, Vault will use Azure Public Cloud.
-- `password_policy` `(string: "")` - Specifies a [password policy](/vault/docs/concepts/password-policies) to
-  use when creating dynamic credentials. Defaults to generating an alphanumeric password if not set.
 - `root_password_ttl` `(string: 182d)` - Specifies how long the root password is valid for in Azure when
   rotate-root generates a new client secret. Uses [duration format strings](/vault/docs/concepts/duration-format).
 
@@ -48,7 +46,6 @@ service principals. Environment variables will override any parameters set in th
   "client_id": "e607c4...",
   "client_secret": "9a6346...",
   "environment": "AzureGermanCloud",
-  "password_policy": "azure_policy",
   "root_password_ttl": "48d"
 }
 ```
@@ -76,7 +73,6 @@ $ vault write azure/config \
     client_id="e607c4...",
     client_secret="9a6346...",
     environment="AzureGermanCloud",
-    password_policy="azure_policy"
 ```
 
 </Tab>