[ci/web] update mymindstorm/setup-emsdk to v12

(cherry picked from commit dcb974700b35837ee13e1bd3f170a979ee0af03d)

.github/workflows/web_builds.yml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v3
 
       - name: Set up Emscripten latest
-        uses: mymindstorm/setup-emsdk@v11
+        uses: mymindstorm/setup-emsdk@v12
         with:
           version: ${{env.EM_VERSION}}
           actions-cache-folder: ${{env.EM_CACHE_FOLDER}}