fix cmake config

[TingDaoK]

• MQTT_WITH_WEBSOCKETS has been removed, but the cmake config was not updated with it
• Also, remove the dependency on aws-c-io, as it's covered by aws-c-http already.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Patch coverage: 37.65% and project coverage change: -0.93 ⚠️

Comparison is base (a661c9d) 81.20% compared to head (1a1e05d) 80.28%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #294      +/-   ##
==========================================
- Coverage   81.20%   80.28%   -0.93%     
==========================================
  Files          18       18              
  Lines        7322     7572     +250     
==========================================
+ Hits         5946     6079     +133     
- Misses       1376     1493     +117     

Impacted Files	Coverage Δ
source/client_impl_shared.c	80.95% <ø> (+3.67%)	⬆️
source/mqtt.c	94.59% <ø> (ø)
source/mqtt3_to_mqtt5_adapter.c	42.50% <35.64%> (-33.70%)	⬇️
source/client.c	69.17% <80.00%> (+3.57%)	⬆️

... and 1 file with indirect coverage changes

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