Add validation for invalid definition IDs in config utilities

[Copilot]

The push-again.yml workflow crashed with TypeError: Cannot read properties of undefined (reading 'path') when given definition ID "base" (which no longer exists - split into base-alpine, base-debian, base-ubuntu).

Changes

• Added validation in getDefinitionPath() to check allDefinitionPaths[definitionId] exists before property access

Throws descriptive error listing available definition IDs:

// Before: TypeError: Cannot read properties of undefined (reading 'path')

// After:
throw new Error(`Invalid definition ID 'base'. Available definition IDs are: anaconda, base-alpine, base-debian, base-ubuntu, cpp, dotnet, go, java, java-8, javascript-node, jekyll, miniconda, php, python, ruby, rust, typescript-node, universal`);

The workflow now fails fast with actionable feedback when given invalid input.

Original prompt

Fix the failing GitHub Actions workflow Build and push images
Analyze the workflow logs, identify the root cause of the failure, and implement a fix.
Job ID: 61482772579
Job URL: https://github.com/devcontainers/images/actions/runs/21361795756/job/61482772579

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[Copilot]

Pull request overview

This PR adds input validation to prevent crashes when invalid definition IDs are provided to the getDefinitionPath() function. The issue was discovered when the push-again.yml workflow was invoked with the definition ID "base", which no longer exists after being split into base-alpine, base-debian, and base-ubuntu.

Changes:

• Added validation in getDefinitionPath() to check if a definition ID exists before accessing its properties
• Throws a descriptive error message listing all available definition IDs when an invalid ID is provided