Fixes https://github.com/github/vscode-github-actions/issues/405
YAML anchors (&name) and aliases (*name) are now properly supported.
When an alias is encountered during parsing, it is resolved to its
anchored value, making aliases transparent to the rest of the system.
Changes:
- workflow-parser: Handle isAlias nodes in YamlObjectReader.getNodes()
- languageservice: Add tests for various anchor/alias patterns
Test cases:
- Anchors in env mappings
- Multiple aliases to same anchor
- Anchors in matrix strategy
- Anchors in steps
- Scalar anchors (e.g., runs-on)
eric sciple