Qiskit / qiskit / 13503185103

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Commit Message

Remove condition/c_if, duration, and unit from instructions (#13506)

* Remove condition/c_if, duration, and unit from instructions

This commit removes the per instruction attributes for condition,
duration, and unit. These attributes were deprecated in 1.3.0. Besides
the label these attributes were the only mutable state for singleton
instructions and removing them simplifies what needs to be tracked for
instructions in both Python and rust. The associated methods and classes
that were previously dependent on these attributes are also removed as
they no longer serve a purpose. The removal of condition in particular
removes a lot of logic from Qiskit especially from the transpiler
because it was a something that needed to be checked outside of the
normal data model for every operation.

This PR simplifies the representation of this extra mutable state in
Rust by removing the `ExtraInstructionAttributes` struct and replacing
it with a `Option<Box<String>>`. The `Option<Box<String>>` is used
instead of the simpler `Option<String>` because this this reduces the
size of the label field from 24 bytes for `Option<String>` to 8 bytes
for `Option<Box<String>>` with an extra layer of pointer indirection
and a second heap allocation. This will have runtime overhead when
labels are set, but because the vast majority of operations don't set
labels the tradeoff for optimizing for the None case makes more sense.
Another option would have been to use `Box<str>` here which is the
equivalent of `Box<[u8]>` (where `String` is the equivalent to
`Vec<u8>`) and from a runtime memory tradeoff would be a better
choice for this application if labels were commonly used as labels
aren't growable. But that requires 16 bytes instead of 8 and we'd be
wasting an additional 8 bytes for each instruction in the circuit which
isn't worth the cost.

* Update random_circuit

* Update more tests

* Fix new scheduling pass implementation

* Fix clippy::redundant_closure

* Add release no... (continued)

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382 of 439 new or added lines in 80 files covered. (87.02%)

189 existing lines in 27 files now uncovered.

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