adding copy argument to QFTGate.__array__ (backport #12979)

[mergify]

Summary

Fixes numpy support for QFTGate: the QFT gate PR was developed in parallel with #11999 and did not get the required upgrade.

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This is an automatic backport of pull request #12979 done by [Mergify](https://mergify.com).

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[coveralls]

Pull Request Test Coverage Report for Build 10455010104

Details

• 2 of 3 (66.67%) changed or added relevant lines in 1 file are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.02%) to 89.836%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/circuit/library/basis_change/qft.py	2	3	66.67%

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	4	91.98%

Totals
Change from base Build 10410180245:	0.02%
Covered Lines:	66814
Relevant Lines:	74373

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💛 - Coveralls