Fix pulse.build() default alignment argument

[TsafrirA]

Summary

Fix #12028 such that pulse.build() will accept AlignmentKind instances as valid input for argument default_alignment.

[qiskit-bot]

One or more of the the following people are requested to review this:

• @Qiskit/terra-core
• @nkanazawa1989

[coveralls]

Pull Request Test Coverage Report for Build 8315587198

Details

• 3 of 3 (100.0%) changed or added relevant lines in 1 file are covered.
• 21 unchanged lines in 3 files lost coverage.
• Overall coverage remained the same at 89.288%

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Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	93.81%
crates/qasm2/src/lex.rs	2	91.69%
crates/qasm2/src/parse.rs	18	96.69%

Totals
Change from base Build 8310563987:	0.0%
Covered Lines:	59783
Relevant Lines:	66955

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💛 - Coveralls

[nkanazawa1989]

Thanks for the bugfix. Alternatively we can make AlignmentKind hashable, but this fix looks more straightforward.