Use interpreter from $PATH instead of absolute paths in various scripts using /usr/bin/env (#9689)

On NixOS, `bash` isn't under `/bin/bash` but rather in some directory in `$PATH`. Locally, I've been patching those scripts to make them work.

`/usr/bin/env` seems to be the only [portable way](https://unix.stackexchange.com/questions/29608/why-is-it-better-to-use-usr-bin-env-name-instead-of-path-to-name-as-my) to use binaries from the PATH as interpreters.

Signed-off-by: Quentin Gliech <quentingliech@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/demo/clean.sh b/demo/clean.sh
index 418ca9457e..6b809f6e83 100755
--- a/demo/clean.sh
+++ b/demo/clean.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -e