Apply transform program to diagonalizing_gates in specs

[lillian542]

Context:
If the diagonalizing gates of a circuit contain unsupported gates, the decomposition isn't applied before deciding how many gates there are

Description of the Change:
We take the diagonalizing gates and apply the preprocess transform program (at the level specs was called with) on the gates before counting them for the num_diagonalizing_gates spec.

Benefits:
The num_diagonalizing_gates spec respects the level kwarg instead of always just returning the answer for the unprocessed version of the tape.

[sc-64695]

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.70%. Comparing base (d9e833a) to head (7bea93b).
Report is 339 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #6290   +/-   ##
=======================================
  Coverage   99.70%   99.70%           
=======================================
  Files         445      445           
  Lines       42260    42263    +3     
=======================================
+ Hits        42137    42140    +3     
  Misses        123      123           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[albi3ro]

👍