Python: Update GitHub Copilot SDK to support BYOK token providers

[droideronline]

Description

Update the Python GitHub Copilot adapter's github-copilot-sdk dependency from 1.0.2 to the latest stable 1.0.11 release so consumers can use the SDK's BYOK bearer token provider API.

Context

The current dependency is pinned to github-copilot-sdk==1.0.2. SDK 1.0.11 adds ProviderConfig.bearer_token_provider, NamedProviderConfig.bearer_token_provider, and the BearerTokenProvider type (Callable[[ProviderTokenArgs], str | Awaitable[str]]). The callback is represented in the SDK session protocol without serializing the Python callable itself.

This is distinct from the earlier provider passthrough issue in #5190: the adapter already forwards default_options into the Copilot session options, but the dependency pin prevents consumers from using the newer callback field.

Validation

• Reviewed the Copilot SDK changelog between 1.0.2 and 1.0.11 for compatibility changes.
• Installed SDK 1.0.11 in the repository virtual environment.
• Ran 218 focused non-integration GitHub Copilot adapter tests successfully.
• Ran Ruff successfully for packages/github_copilot.
• Confirmed the stable 1.0.11 package exports ProviderConfig.bearer_token_provider and BearerTokenProvider.

Scope

Update the package dependency declaration and lockfile entry only. No adapter runtime code changes are required.