[grpc exporter] Handle backoff 1.0 and 2.0

[Yamakaky]

Fixes https://github.com/open-telemetry/opentelemetry-python/issues/2829.

Description

Prevents the use of backoff >= 2.0.0 which has breaking changes that are not handled by the code.

Fixes #2829

Type of change

Please delete options that are not relevant.

• [X] Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• [X] Run locally with pinned version to 1.11.1

Does This PR Require a Contrib Repo Change?

• [ ] Yes. - Link to PR:
• [X] No.

Checklist:

• [X] Followed the style guidelines of this project
• [x] Changelogs have been updated
• [x] Unit tests have been added
• [x] Documentation has been updated

[srikanthccv]

This was originally pinned to strict version but later another contributed made the wide range of acceptable version because their project uses the 2.0. I would rather encourage you to fix the bug instead since the users can still pin the lower version.

[Yamakaky]

Done, though I haven't tested it.

[srikanthccv]

@Yamakaky Please add tests

[Yamakaky]

Oh I see, I'll add that

[srikanthccv]

@Yamakaky we are planning on releasing 1.13/0.34b0 this week or early next week. Please address the comments and get this merged if you would like to see this included in next release.

[Yamakaky]

There it is! I updated to backoff 2.0 for grpc and http.

[Yamakaky]

Hum, I'm not very familiar with tox and how your testing works, so help would be appreciated for fixing the CI issues!

[Yamakaky]

Note: if this can't be merged for 1.13, please at least add the quickfix to require backoff < 2. This repo cannot work with v2.

[srikanthccv]

You could pin it to 1.11.1 so pip doesn't install 2.x.

[Yamakaky]

That's what I did for the first version of my PR. Should I do that again, and keep this long term fix for later?

[srikanthccv]

See #2980