[DEP]: replace backoff dependency with tenacity

[Fenkiou]

Description

backoff library isn't maintained anymore so we had to find a replacement for it. tenacity is very popular one.

Remaining Tasks

Related PRs in other projects (PASQAL developers only)

Additional merge criteria

Breaking changes

Checklist

• The title of the PR follows the right format: [{Label}] {Short Message}. Label examples: IMPROVEMENT, FIX, REFACTORING... Short message is about what your PR changes.

Versioning (PASQAL developers only)

• Update the version of pasqal-cloud in VERSION.txt following the changes in your PR and by using semantic versioning.

Documentation

• Update CHANGELOG.md with a description explaining briefly the changes to the users.

Tests

• Unit tests have been added or adjusted.
• Tests were run locally.

Internal tests pipeline (PASQAL developers only)

• Update and run the internal tests while targeting the branch of this PR.
  If your PR hasn't changed any functionality, it still needs to be validated against internal tests.

After updating the version (PASQAL developers only)

• Open a PR on the internal tests that updates the version used for the pasqal-cloud backward compatibility tests.

[stephenfreelance]

lgtm