Cleanup timeline drawer with schedule analysis pass.

[nkanazawa1989]

Summary

Timeline drawer implements own scheduler but this is no longer necessary since we have implemented absolute-time scheduling pass in #7709.

This PR copies this scheduling outcome to the output circuit and let the timeline drawer use this information. Because this schedule contains t0 for classical registers, now timeline drawer can properly show time slots for classical registers.

Details and comments

from qiskit import QuantumCircuit, transpile
from qiskit.test.mock import FakeMontreal
from qiskit.visualization.timeline import draw as draw_timeline

backend = FakeMontreal()

qct = transpile(
    qc, backend, initial_layout=[0, 1], coupling_map=[[0, 1], [1, 0]], scheduling_method="alap"
)
draw_timeline(qct, show_clbits=True)

[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

[mtreinish]

LGTM, just one small inline comment. Also I think maybe having a test that we raise an Attribute error on an unscheduled circuit would be good just so we have the coverage.

[coveralls]

Pull Request Test Coverage Report for Build 2510201605

• 45 of 55 (81.82%) changed or added relevant lines in 4 files are covered.
• 3 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.01%) to 84.267%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/transpiler/basepasses.py	1	6	16.67%
qiskit/visualization/timeline/core.py	32	37	86.49%

Files with Coverage Reduction	New Missed Lines	%
qiskit/circuit/quantumcircuit.py	3	94.12%

Totals
Change from base Build 2505540605:	-0.01%
Covered Lines:	54816
Relevant Lines:	65050

---

💛 - Coveralls

[mtreinish]

Overall this LGTM, just one question about the release note

[mtreinish]

Did you want to add a deprecation note about visualizing a timeline for an unscheduled/untranspiled circuit?

[nkanazawa1989]

Thanks Matthew I've forgotten to write. Added in 8891220

[mtreinish]

LGTM, thanks for the update