Fix changelog environment variable assignment

Author: RinLit-233-shiroko

.github/workflows/release.yml

@@ -52,7 +52,9 @@ jobs:
         id: generate_changelog
         run: |
           git-cliff --config .git-cliff.toml --tag v${{ env.VERSION }} > CHANGELOG.md
-          echo "CHANGELOG=$(cat CHANGELOG.md)" >> $GITHUB_ENV
+          echo "CHANGELOG<<EOF" >> $GITHUB_ENV
+          cat CHANGELOG.md >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
       
       - name: Create Release
         id: create_release