Add maybe_expr feature for OTP 26

GitHub action Build and Xref on OTP 26 errored with:
```
src/rabbit_quorum_queue.erl:252:9: syntax error before: ok
%  252|         ok ?= rabbit_queue_type_util:check_auto_delete(Q),
%     |         ^
```

Author: ansd

deps/rabbit/src/rabbit_quorum_queue.erl

@@ -6,6 +6,7 @@
 %%
 
 -module(rabbit_quorum_queue).
+-feature(maybe_expr, enable).
 
 -behaviour(rabbit_queue_type).
 -behaviour(rabbit_policy_validator).

deps/rabbit/src/rabbit_stream_queue.erl

@@ -6,6 +6,8 @@
 %%
 
 -module(rabbit_stream_queue).
+-feature(maybe_expr, enable).
+
 -include("mc.hrl").
 
 -behaviour(rabbit_queue_type).