Fix typo

Author: stumbo

.github/workflows/gh-pages.yml

@@ -149,7 +149,7 @@ jobs:
 
       - name: Build
         env:
-          HUGOENVIRONMENT: staging
+          HUGO_ENVIRONMENT: staging
           HUGO_CACHEDIR: ${{ runner.temp }}/hugo_cache
           TZ: America/New York
         run: hugo --gc