fix release.yml: GITHUB_TOKEN sanitized + quote multi-line env values

- GITHUB_TOKEN expression was sanitized to '*** ... }}' by an
  upstream templating pass, breaking YAML parse on Forgejo with
  'did not find expected alphabetic or numeric character' at
  line 223.
- RELEASE_BODY and IS_PRERELEASE are quoted (YAML double-quoted
  string) so the parser accepts multi-line release body content
  sourced from CHANGELOG.md.

Verified locally with yaml.safe_load.

.forgejo/workflows/release.yml

@@ -220,12 +220,18 @@ jobs:
 
       - name: Publier la release Forgejo via l'API REST
         env:
-          GITHUB_TOKEN: *** secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GITHUB_API_URL: ${{ github.api_url }}
           GITHUB_REPOSITORY: ${{ github.repository }}
           TAG: ${{ github.event_name == 'push' && github.ref_name || inputs.tag }}
-          RELEASE_BODY: ${{ env.RELEASE_BODY }}
+          # RELEASE_BODY peut contenir des retours à la ligne et
-          IS_PRERELEASE: ${{ env.IS_PRERELEASE }}
+          # des caractères YAML-réservés (':', '#', etc.) issus du
+          # CHANGELOG.md. On le quote en YAML double-quoted string
+          # pour que le parser Forgejo accepte la valeur multi-ligne.
+          # Sinon : "yaml: line N: did not find expected alphabetic
+          # or numeric character".
+          RELEASE_BODY: "${{ env.RELEASE_BODY }}"
+          IS_PRERELEASE: "${{ env.IS_PRERELEASE }}"
         run: |
           if [[ -z "$TAG" ]]; then
             echo "::error::No tag resolved for the API call."