fix(ext/flash): Fix panic when JS caller doesn't consume request body (…

…denoland#16173)



If the JS handler gets a POST, PUT, or PATCH request, but doesn't
`await` the body, deno would panic because it will try to read the body
even though the request has already been handled.

Not sure how/where to test this case, so I could use some help with
that.

ext/flash/lib.rs

@@ -754,7 +754,11 @@ async fn op_flash_read_body(
  .as_mut()
  .unwrap()
  };
- let tx = ctx.requests.get_mut(&token).unwrap();
+ let tx = match ctx.requests.get_mut(&token) {
+ Some(tx) => tx,
+ // request was already consumed by caller
+ None => return 0,
+ };
 
  if tx.te_chunked {
  let mut decoder =