Support standalone authentication for `bicep deploy` without requiring Azure CLI or Azure PowerShell

**Is your feature request related to a problem? Please describe.**

Currently, `bicep deploy` relies on an external tool such as Azure CLI, Azure PowerShell, or service principal environment variables to provide authentication. This means users must install additional tooling (e.g., `az` or `pwsh`), which creates unnecessary dependencies.
PowerShell is not shipped out-of-the-box on Windows, macOS, or Linux, and requiring Azure CLI or PowerShell makes `bicep deploy` less portable and harder to adopt in minimal environments or containerized workflows.

**Describe the solution you'd like**

I’d like `bicep deploy` to support standalone authentication flows, such as `InteractiveBrowserCredential` and `DeviceCodeCredential` from the Azure.Identity library. This would allow users to run deployments without requiring Azure CLI or PowerShell installed, making the CLI more self-contained and easier to use in environments where minimizing dependencies is important.

Related conversation at #17949.

Start at the bicep deploy command and review the related conversation in issue #17949, then examine how authentication currently comes from Azure CLI, Azure PowerShell, or service principal environment variables. The work is done when deployments can use Azure.Identity flows such as InteractiveBrowserCredential or DeviceCodeCredential without either external tool installed.

Written by the indexing model from the issue text.