Refactor: replace VoucherManager by voucher service from sdk

[1yam]

This PR remove voucher logic from CLI to go to SDK.
And replace call from the voucher manager to client.voucher...

Related ClickUp, GitHub or Jira tickets : ALEPH-542

Self proofreading checklist

• The new code clear, easy to read and well commented.
• New code does not duplicate the functions of builtin or popular libraries.
• An LLM was used to review the new code and look for simplifications.
• New classes and functions contain docstrings explaining what they provide.
• All new code is covered by relevant tests

Changes

This pull request refactors how voucher-related functionality is accessed in the codebase. The main change is the removal of the local VoucherManager implementation and the switch to using voucher methods provided by the upstream aleph-sdk-python package. This results in cleaner code and reduces maintenance overhead by delegating voucher logic to the SDK. The dependency on aleph-sdk-python is also updated to a specific branch that includes the necessary voucher features.

Dependency and SDK integration:

• Updated the aleph-sdk-python dependency in pyproject.toml to point to a specific GitHub branch (1yam-voucher-service) that provides the required voucher functionality.
• Removed the local VoucherManager class and all related voucher logic from src/aleph_client/voucher.py, fully delegating voucher operations to the SDK.

Codebase refactoring and simplification:

• Replaced all usages of VoucherManager in src/aleph_client/commands/account.py and src/aleph_client/commands/instance/__init__.py with the new AuthenticatedAlephHttpClient SDK client and its voucher methods, such as get_vouchers and fetch_vouchers_by_chain. [1] [2] [3] [4] [5]
• Cleaned up imports to remove references to the now-deleted VoucherManager. [1] [2]

These changes streamline voucher handling, leverage upstream improvements, and reduce duplicated logic in the codebase.

How to test

• Create instancee using NFT
• aleph account vouchers

Notes

Depends on : aleph-im/aleph-sdk-python#225

[github-actions]

Failed to retrieve llama text: POST 500: {"error": "500: Unhandled error during initialisation"}

[nesitor]

Seems that tests are failing here, but also will be good to add unit tests ensuring that proper methods are called from the SDK.