[Regression in v1.0.42] setup-bun token usage broken on GHES

**Describe the bug**
[This commit](https://github.com/anthropics/claude-code-action/commit/4ce5f178c22b5a6494fb3246ecd96bce6ac99c67) (merged in #861) breaks installs GitHub Enterprise Server (GHES) because it expects a token valid for github.com.

**To Reproduce**
Steps to reproduce the behavior:

1. Run GitHub Enterprise Server
2. Setup GitHub Actions workflow using anthropics/claude-code-action per official docs
3. Trigger action
4. See error

**Expected behavior**
This action, along with the setup-bun action, should minimize use of GitHub API to avoid API limits rather than requiring token usage. Alternatively, expose a separate input to be passed to setup-bun rather than defaulting to the token passed to claude-code-action as this one is needed for interacting with GHES repositories.

**Screenshots**

**Workflow yml file**

**API Provider**

[ ] Anthropic First-Party API (default)
[ ] AWS Bedrock
[ ] GCP Vertex

**Additional context**
N/A