Bump skills/action-text-variables from 2 to 3

Bumps [skills/action-text-variables](https://github.com/skills/action-text-variables) from 2 to 3.
- [Release notes](https://github.com/skills/action-text-variables/releases)
- [Commits](skills/action-text-variables@v2...v3)

---
updated-dependencies:
- dependency-name: skills/action-text-variables
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Author: dependabot[bot]

.github/workflows/0-start-exercise.yml

@@ -75,7 +75,7 @@ jobs:
 
       - name: Build comment - add step content
         id: build-comment
-        uses: skills/action-text-variables@v2
+        uses: skills/action-text-variables@v3
         with:
           template-file: ${{ env.STEP_1_FILE }}
           template-vars: |