with ESPAsyncWebServer 3.3.0, the setAuthentication() method became
deprecated and a replacement method was provided which acts as a shim
and uses the new middleware-based approach to setup authentication. in
order to eventually apply a changed "read-only access allowed" setting,
the setAuthentication() method was called periodically. the shim
implementation each time allocates a new AuthenticationMiddleware and
adds it to the chain of middlewares, eventually exhausting the memory.
we now use the new middleware-based approach ourselves and only add the
respective AuthenticatonMiddleware instance once to the respective
websocket server instance.
a regression where enabling unauthenticated read-only access is not
applied until reboot is also fixed. all the AuthenticationMiddleware
instances were never removed from the chain of middlewares when calling
setAuthentication("", "").
