ci(publish): try to fix command that appends to GITHUB_ENV

Author: goldenstein64

.github/workflows/publish.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Get Rockspec Version
         run: |
           [[ "${{ github.ref_name }}" =~ ^v(.+)$ ]]
-          "spec_version=${BASH_REMATCH[1]}" >> $env:GITHUB_ENV
+          echo "spec_version=${BASH_REMATCH[1]}" >> $env:GITHUB_ENV
 
       - name: Publish to LuaRocks
         run: |