Update tests to account for new QFT subroutine

[comp-phys-marc]

Context: Some lightning tests need to be updated to use the new Subroutine abstraction properly.

Description of the Change: Update the way we get QFT operators and matrices.

Benefits: Tests all passing.

Possible Drawbacks: N/A

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit .github/CHANGELOG.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.31%. Comparing base (274fd42) to head (99ce112).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1358      +/-   ##
==========================================
- Coverage   95.69%   94.31%   -1.39%     
==========================================
  Files         278      207      -71     
  Lines       40965    29123   -11842     
==========================================
- Hits        39200    27466   -11734     
+ Misses       1765     1657     -108     

Flag	Coverage Δ
unit_tests	94.31% <100.00%> (-1.39%)	⬇️

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[andrijapau]

Thanks @comp-phys-marc ! Running the LL PTM against your branch here.

[comp-phys-marc]

We are reverting the changes that made this fix necessary.