Remove ::set-output

set-output is deprecated - using the suggested change from

https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Author: leedxw

.github/workflows/theme.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Get Composer Cache Directory
         id: composer-cache
         run: |
-          echo "::set-output name=dir::$(composer config cache-files-dir)"
+          echo "dir=$(composer config cache-files-dir)" >> "$GITHUB_OUTPUT"
       - uses: actions/cache@v4
         with:
           path: ${{ steps.composer-cache.outputs.dir }}