Bump bluwy/substitute-string-action from 2 to 3 (#4783)

Bumps [bluwy/substitute-string-action](https://github.com/bluwy/substitute-string-action) from 2 to 3.
- [Release notes](https://github.com/bluwy/substitute-string-action/releases)
- [Commits](https://github.com/bluwy/substitute-string-action/compare/v2...v3)

---
updated-dependencies:
- dependency-name: bluwy/substitute-string-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/flatpak.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Install xmlstarlet
       run: sudo apt -y install xmlstarlet
     - name: Create Version Variable
-      uses: bluwy/substitute-string-action@v2
+      uses: bluwy/substitute-string-action@v3
       id: sub
       with:
         _input-text: ${{ fromJson(steps.api_results.outputs.result).tag_name }}