Fix the shebang on the e2e script by

1. Removing a
[zero-width no-break space](https://www.compart.com/en/unicode/U+FEFF)before
the `#!`
2. Changing the path from `/bin/env` to `/usr/bin/env`, which is correct on
most (all?) modern Unix-like systems.

Signed-off-by: Ben Cotton <ben@kusari.dev>

internal/testing/e2e/e2e

@@ -1,4 +1,4 @@
-#!/bin/env bash
+#!/usr/bin/env bash
 
 #
 # Copyright 2023 The GUAC Authors.