Fix Python 3.12 / Apple Silicon compatibility (pyobjc pin, keyring backend)

[rpallred]

Description:

This PR fixes three cascading failures that prevent Zowie 1.3.0 from installing or running on Apple Silicon Macs with Python 3.12.

Failure 1: pyobjc circular import (Issue #19)

The shiv binary bundles pyobjc-core 9.0.1, compiled for Intel. On Apple Silicon with Python 3.12, it raises:

ImportError: cannot import name '_objc' from partially initialized module 'objc'
(most likely due to a circular import)

Failure 2: pyobjc-core will not build from source under Python 3.12

Installing Zowie via pipx or pip triggers a build of pyobjc-core 9.0.1 from source, which fails because the pinned version's setup.py calls pkg_resources, a module removed from Python 3.12's default environment:

ModuleNotFoundError: No module named 'pkg_resources'
ERROR: Failed to build 'pyobjc-core' when getting requirements to build wheel

Failure 3: keyring.backends.OS_X removed in keyring ≥ 24

Once pyobjc is resolved by installing a newer version first, a third failure surfaces. keyring_utils.py imports directly from keyring.backends.OS_X, a backend removed in keyring 24.x:

ModuleNotFoundError: No module named 'keyring.backends.OS_X'

Changes in this PR

• Relaxed pyobjc-core and related pyobjc framework version pins from ==9.0.1 to >=9.0.1, allowing pip to install a current, native ARM build that compiles cleanly against Python 3.12
• Fixed the keyring.backends.OS_X import in keyring_utils.py with a try/except fallback to keyring.backends.macOS, preserving backward compatibility with older keyring versions

Tested environment

• Hardware: MacBook Pro M4 Max
• macOS: Tahoe 26.5
• Python: 3.12 (Homebrew)
• Zowie: 1.3.0

[gemini-code-assist]

Code Review

This pull request relaxes the version constraints for pyobjc dependencies in requirements.txt from exact versions to >= 9.0.1 and updates keyring_utils.py to support importing from macOS keyrings with a fallback to OS_X. The reviewer recommends pinning the pyobjc dependencies to a specific newer version (such as 10.3) instead of using minimum version bounds to ensure reproducible builds and avoid potential breaking changes.

[gemini-code-assist]

For applications, it is a best practice to pin dependencies to exact versions in requirements.txt to ensure reproducible builds and prevent unexpected breakages from future dependency updates.

Using >= 9.0.1 without an upper bound might install a much newer version of pyobjc (e.g., a future major release) that could introduce breaking changes.

Consider pinning to a specific newer version of pyobjc that supports Python 3.12 and Apple Silicon (such as 10.3).

pyobjc-core                      == 10.3
pyobjc-framework-AppleScriptKit  == 10.3
pyobjc-framework-AppleScriptObjC == 10.3