Reset backend options to default in get_backend

[merav-aharoni]

Summary

Reset backend.options to default in IBMProvider.get_backend().

Details and comments

See #489 - Please consider if you agree with my approach.
If we all agree, this should also be fixed in qiskit_ibm_runtime.

[coveralls]

Pull Request Test Coverage Report for Build 5847725856

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Details

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.008%) to 51.089%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit_ibm_provider/ibm_provider.py	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
qiskit_ibm_provider/ibm_provider.py	1	52.67%

Totals
Change from base Build 5835664226:	-0.008%
Covered Lines:	3307
Relevant Lines:	6473

---

💛 - Coveralls

[merav-aharoni]

This is also related to #486. However there, it is not the options that need to be reset, but the entire config. Do we want to do this?

[kt474]

On the main branch I ran the following code snippet - aren't the backend options already reset to default? Or am I missing something

[merav-aharoni]

On the main branch I ran the following code snippet - aren't the backend options already reset to default? Or am I missing something

This is very strange, because I get

4000
200
200

For the same code. Can you double check you are indeed running on the main branch?

[kt474]

For the same code. Can you double check you are indeed running on the main branch?

Running in a custom anaconda env I now get the same results as you - not sure what causes this discrepancy but change LGTM