Actually fail on clippy failures (#7619)

Before the change to `script/clippy`, bash ignored first `clippy`
invocation failure and CI moved on with Linux errors and warnings
emitted.


Release Notes:

- N/A

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>

script/clippy

@@ -1,4 +1,6 @@
-#!/bin/bash
+#!/usr/bin/env bash
+
+set -euxo pipefail
 
 # clippy.toml is not currently supporting specifying allowed lints
 # so specify those here, and disable the rest until Zed's workspace