Revert "Work around sl-select bug. (#3139)" (#3153)

This reverts commit 4ad8db28dd.

templates/spa.html

@@ -88,14 +88,6 @@ limitations under the License.
   See https://github.com/GoogleChrome/chromium-dashboard/issues/2014
   #}
   <script type="module" nonce="{{nonce}}" src="/static/js/shared.min.js?v={{app_version}}"></script>
-
-  {# Work-around for bug in sl-select:
-     https://github.com/GoogleChrome/chromium-dashboard/issues/3137
-  #}
-  <script nonce="{{nonce}}">
-    let process = { env: {} };
-  </script>
-
 </body>
 
 </html>