Fix mypy errors (compiler)

[Randl]

Summary

Following discussion, I'm splitting #8187 by module.

Details and comments

qiskit/compiler/assembler.py:209: error: Module not callable  [operator]
qiskit/compiler/assembler.py:230: error: Module not callable  [operator]
qiskit/compiler/scheduler.py:72: error: "Backend" has no attribute "instruction_schedule_map"  [attr-defined]
qiskit/compiler/scheduler.py:74: error: "Backend" has no attribute "meas_map"  [attr-defined]
qiskit/compiler/scheduler.py:76: error: "Backend" has no attribute "dt"  [attr-defined]
qiskit/compiler/scheduler.py:83: error: "Backend" has no attribute "defaults"  [attr-defined]
qiskit/compiler/scheduler.py:94: error: "Backend" has no attribute "configuration"  [attr-defined]
qiskit/compiler/scheduler.py:97: error: "Backend" has no attribute "configuration"  [attr-defined]
qiskit/compiler/sequencer.py:56: error: "Backend" has no attribute "defaults"  [attr-defined]
qiskit/compiler/sequencer.py:60: error: "Backend" has no attribute "configuration"  [attr-defined]
qiskit/compiler/sequencer.py:64: error: "Backend" has no attribute "configuration"  [attr-defined]
qiskit/compiler/transpiler.py:264: error: Item "QuantumCircuit" of "Union[QuantumCircuit, List[QuantumCircuit]]" has no attribute "__iter__" (not iterable)  [union-attr]
qiskit/compiler/transpiler.py:271: error: Incompatible return value type (got "Union[CircuitInstruction, QuantumCircuit]", expected "Union[QuantumCircuit, List[QuantumCircuit]]")  [return-value]
qiskit/compiler/transpiler.py:316: error: No overload variant of "__getitem__" of "list" matches argument type "str"  [call-overload]
qiskit/compiler/transpiler.py:316: note: Possible overload variants:
qiskit/compiler/transpiler.py:316: note:     def __getitem__(self, SupportsIndex) -> Dict[Any, Any]
qiskit/compiler/transpiler.py:316: note:     def __getitem__(self, slice) -> List[Dict[Any, Any]]
qiskit/compiler/transpiler.py:334: error: Argument 1 to "zip" has incompatible type "Union[QuantumCircuit, List[QuantumCircuit]]"; expected "Iterable[QuantumCircuit]"  [arg-type]
qiskit/compiler/transpiler.py:334: error: Argument 1 to "zip" has incompatible type "Union[QuantumCircuit, List[QuantumCircuit]]"; expected "Iterable[Any]"  [arg-type]
qiskit/compiler/transpiler.py:338: error: Argument 1 to "zip" has incompatible type "Union[QuantumCircuit, List[QuantumCircuit]]"; expected "Iterable[QuantumCircuit]"  [arg-type]
qiskit/compiler/transpiler.py:358: error: Incompatible return value type (got "Union[CircuitInstruction, QuantumCircuit]", expected "Union[QuantumCircuit, List[QuantumCircuit]]")  [return-value]

The first two appear to be some kind of mypy problem: it can't distinguish between function and same named module due to import structure?
The next some are due to the fact that Backend class do not define any attributes, but rather its subclasses do. Finally, some errors are due to type cast mypy misses -- can be solved by explicit cast or changing variable name probably?

[qiskit-bot]

Thank you for opening a new pull request.

Before your PR can be merged it will first need to pass continuous integration tests and be reviewed. Sometimes the review process can be slow, so please be patient.

While you're waiting, please feel free to review other open PRs. While only a subset of people are authorized to approve pull requests for merging, everyone is encouraged to review open pull requests. Doing reviews helps reduce the burden on the core team and helps make the project's code better for everyone.

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

• @Qiskit/terra-core

[Randl]

This looks like genuine type error, maybe it should be unique_transpile_args[coupling_map]?

[Randl]

Meanwhile closing since there are no meanigful changes left

[coveralls]

Pull Request Test Coverage Report for Build 5058128185

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 9 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.09%) to 85.961%

---

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	93.76%
qiskit/transpiler/passes/synthesis/unitary_synthesis.py	1	90.27%
crates/accelerate/src/sabre_swap/mod.rs	2	99.53%
crates/qasm2/src/lex.rs	5	91.65%

Totals
Change from base Build 5050064110:	0.09%
Covered Lines:	71348
Relevant Lines:	83000

---

💛 - Coveralls