Avoid exploring extraneous minima in the cut-finder search space

[ibrahim-shehzad]

A certain step in the cut-finder explores multiple minima of the cost function. This step, however, is only relevant when we have LOCC or LO blackbox/parallel gate cut QPD assignments. As such, it is unnecessary for the LO circuit cutting that we currently support. Disabling the search for multiple minima also helps speed up the performance of the cut finder. This was especially relevant for certain QAOA circuits that were reported to us, which involved multiple Rzz gates with $\theta =0$ (in which case the cost of cutting each of these gates is 1). Telling the cut finder to stop at the first minimum stops it from exploring an evergrowing list of states (since no pruning of states can take place when the cost of each additional gate cut just gives us a multiplicative factor of 1 to the overall cost). This PR aims to fix all of this, simply by setting the default value of certain stop_at_first_min flags to True.

[coveralls]

Pull Request Test Coverage Report for Build 9083375618

Details

• 13 of 13 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.004%) to 95.497%

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Totals
Change from base Build 9021914548:	0.004%
Covered Lines:	3499
Relevant Lines:	3664

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💛 - Coveralls

[caleb-johnson]

Could do a release note if we think the cut-finding performance is noticeable enough in general usage.