Fix regex pattern for exception thrown in tests

[mlxd]

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Context: This updates a given test to match a new exception string thrown by PennyLane.

Description of the Change: As above.

Benefits: Ensures all tests pass.

Possible Drawbacks: None

Related GitHub Issues:

[github-actions]

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[github-actions]

Test Report (Linux, Kokkos, and Kokkos Kernels) on Ubuntu

           1 files  ±0             1 suites  ±0   2s ⏱️ -1s
       975 tests ±0         975 ✔️ ±0  0 💤 ±0  0 ❌ ±0 
229 280 runs  ±0  229 280 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit e895e92. ± Comparison against base commit c71a74c.

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

Merging #318 (e895e92) into master (c71a74c) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #318   +/-   ##
=======================================
  Coverage   99.79%   99.79%           
=======================================
  Files          38       38           
  Lines        3920     3920           
=======================================
  Hits         3912     3912           
  Misses          8        8           

Impacted Files	Coverage Δ
pennylane_lightning/_version.py	100.00% <100.00%> (ø)

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[chaeyeunpark]

Looks good to me, Lee.

[multiphaseCFD]

Thanks @mlxd ! Look fine to me.