Feature Request: Add support for Bun package manager

[coolcline]

Is your feature request related to a problem? Please describe.
Currently, vsce hardcodes the use of npm for running prepublish scripts (npm run vscode:prepublish). This causes issues when using alternative package managers like Bun, as the command fails with "npm: command not found" even when the project is properly configured to use Bun.

Describe the solution you'd like
I propose adding support for different package managers, specifically Bun, in the following ways:

1. Auto-detect the package manager being used in the project (by checking for bun.lockb, package-lock.json, yarn.lock, etc.)
2. Add a configuration option to explicitly specify which package manager to use (e.g., --package-manager=bun)
3. Use the detected/specified package manager when running scripts instead of hardcoding npm

Describe alternatives you've considered
Current workarounds include:

• Installing npm alongside Bun (not ideal, adds unnecessary dependencies)
• Using the --no-dependencies flag (doesn't work as the npm command is still hardcoded)

Additional context
Bun is gaining popularity as a fast, all-in-one JavaScript runtime and package manager. Supporting it would improve the developer experience for teams using Bun in their VS Code extension projects.

Example of a project using Bun:

json
{
    "scripts": {
    "vscode:prepublish": "bun run package",
    "package": "bun run build:webview && bun run check-types && bun run lint"
    }
}

Environment:

• vsce version: 2.15.0
• OS: macOS
• Package Manager: Bun 1.1.42