Disabled nightly tests for straightdope example notebooks

[sandeep-krishnamurthy]

This is a tracking issue for re-enabling all the straight dope nightly notebook tests.

1. chapter05_recurrent-neural-networks/rnns-gluon. Ref - [MXAPPS-581] Disable a long test in the SD nightly. #12326
2. chapter08_computer-vision/visual-question-answer Ref - [MXAPPS-581] Disable an additional long test in the SD nightly. #12343

@vishaalkapoor

[vishaalkapoor]

Thanks @sandeep-krishnamurthy please add me as an assignee.

[marcoabreu]

Sorry, we can't assign to non committers

[vishaalkapoor]

@sandeep-krishnamurthy @marcoabreu Please feel free to close as #12744 addressing this has been merged. Thanks!

[piyushghai]

@sandeep-krishnamurthy Can you close this issue ?