`aspire update --self --non-interactive` fails without `--channel`

[ElanHasson]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

aspire update --self --non-interactive fails with an interactive prompt error, even though --non-interactive is explicitly passed:

$ aspire update --self --non-interactive
❌ An unexpected error occurred: Interactive input is not supported in this environment.
   Use the --non-interactive flag or ensure the CLI is running in an interactive terminal.

The command presumably needs to prompt for a channel selection (stable/daily), but --non-interactive doesn't cause it to default to a sensible channel — it just crashes.

Adding --channel daily (or --channel stable) makes it work:

$ aspire update --self --channel daily --non-interactive
✔  Updated to version: 13.3.0-preview.1.26163.4+...

Expected Behavior

When --non-interactive is passed without --channel, the command should default to a sensible channel (e.g., match the current installed channel, or default to stable) instead of attempting an interactive prompt and crashing.

Steps To Reproduce

1. Run aspire update --self --non-interactive in any non-interactive terminal (CI, piped shell, etc.)
2. Observe the error about interactive input not being supported

Exceptions (if any)

❌ An unexpected error occurred: Interactive input is not supported in this environment.
   Use the --non-interactive flag or ensure the CLI is running in an interactive terminal.

.NET Version info

.NET SDK:
 Version:           10.0.103
 Commit:            c2435c3e0f
 Workload version:  10.0.102
 MSBuild version:   18.0.11+c2435c3e0

Runtime Environment:
 OS Name:     ubuntu
 OS Version:  24.04
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /home/elan/.local/share/dnvm/dn/sdk/10.0.103/

Host:
  Version:      10.0.3
  Architecture: x64
  Commit:       c2435c3e0f

.NET SDKs installed:
  8.0.418 [/home/elan/.local/share/dnvm/dn/sdk]
  10.0.100 [/home/elan/.local/share/dnvm/dn/sdk]
  10.0.103 [/home/elan/.local/share/dnvm/dn/sdk]

Anything else?

• Aspire CLI version: 13.3.0-preview.1.26163.4+8aba30e0f288ebeee09e7322732e3ee917aaea39 (daily)
• IDE: Claude Code 2.1.76
• Platform: Linux (WSL2, Ubuntu 24.04)

This is particularly problematic for CI/CD pipelines and automation scripts that need to keep the Aspire CLI up to date non-interactively.

Related: #15252 (aspire update --self doesn't update .config/dotnet-tools.json)