Revert "Add usage tracking fetch"

This reverts commit e248bcde.

public/empty.txt

-nothing here.
\ No newline at end of file

src/App.svelte

@@ -2,12 +2,6 @@
   import BivariateData from "./components/BivariateData.svelte";
 
   import UnivariateData from "./components/UnivariateData.svelte";
-
-  try {
-    fetch("./empty.txt")
-  } catch (e) {
-    // do nothing
-  }
 </script>
 
 <section class="hero is-primary">