completions incorrectly appear when typing `.` in a comment

**Describe the bug**
when typing `.` in a comment, completions incorrectly appear

**To Reproduce**
Steps to reproduce the behavior:
1. create a workflow yaml with the following content:
```yaml
jobs:
#
```
3. type a `.` after the `#`

**Expected behavior**
no completions

**Screenshots**

**Extension Version**
0.32.3

Reproduce the issue in VS Code using the workflow YAML shown in the report and the GitHub Actions extension version 0.32.3. Trace the completion behavior for a period typed after a YAML comment; done means no completions appear in that context while normal completions remain available elsewhere.

索引モデルが issue の本文から書いたものです。