Completed the implementation of the aforementioned environment setting into the OAuth workflows.
Documented the aforementioned setting in the Environment-variables.md wiki document.
This commit adds support for the `oidc_oauth_metadata_url` configuration
option. This option specifies the URL of the OIDC server's
metadata endpoint, which contains information about the OIDC server's
endpoints, supported scopes, and other configuration details. By using this
option, we can ensure compatibility with different OIDC servers and reduce
the risk of errors due to manual endpoint configuration.
