Unitary synthesis bug fix (backport #15286)

[mergify]

Summary

A small bug fix to the unitary synthesis pass in the case that a non-default plugin in specified, and this plugin supports the basis gates but not the target. When target is specified, it should override both basis_gates and coupling_map, that is the plugin should be called with basis_gates and coupling_map coming from the target, and not from the standalone arguments. Previously the argument coupling_map was indeed taken from the target, but basis_gates were not.

Needed for #14952.

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This is an automatic backport of pull request #15286 done by [Mergify](https://mergify.com).

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[coveralls]

Pull Request Test Coverage Report for Build 19099329280

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 6 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.05%) to 88.438%

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Files with Coverage Reduction	New Missed Lines	%
crates/circuit/src/parameter/parameter_expression.rs	1	82.79%
crates/transpiler/src/passes/sabre/layout.rs	1	86.36%
crates/qasm2/src/lex.rs	4	91.75%

Totals
Change from base Build 18941246851:	0.05%
Covered Lines:	92411
Relevant Lines:	104492

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💛 - Coveralls