This commit removes event listeners from the `script` element once loading is
complete. If the element is not garbage collected properly, in Firefox, the script
element still appears in the memory tree view, captured by
`__zone_symbol__loadfalse -> HTMLScriptElement -> GC Roots`. We should always be good
citizens and clean up event listeners when we no longer need them, as browser's garbage
collectors work differently. Calling `remove()` on the node doesn't guarantee that the
node can be collected.
PR Close#57877