[bug#74962] [PATCH v3 2/5] etc/guix-install.sh: Explicit shebang to use /usr/bin/env.

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Having an explicit shebang tells something useful: we depend on Bash.  Tools
such as shellcheck make use of it.  The original technical reason for avoiding
/usr/bin/env is no more (Guix System lacking it).

* etc/guix-install.sh: Adjust shebang.  Remove conditional 'exec bash' further
block below.

Change-Id: I3c92a9e58fe11610dfbf74dbbd4b1ac8852abcf0
---

(no changes since v1)

 etc/guix-install.sh | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/etc/guix-install.sh b/etc/guix-install.sh
index f07b2741bb..481eb6f12a 100755
--- a/etc/guix-install.sh
+++ b/etc/guix-install.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 # GNU Guix --- Functional package management for GNU
 # Copyright © 2017 sharlatan <sharlatanus@gmail.com>
 # Copyright © 2018 Ricardo Wurmus <rekado@elephly.net>
@@ -9,7 +9,7 @@
 # Copyright © 2020 Daniel Brooks <db48x@db48x.net>
 # Copyright © 2021 Jakub Kądziołka <kuba@kadziolka.net>
 # Copyright © 2021 Chris Marusich <cmmarusich@gmail.com>
-# Copyright © 2021, 2022, 2023 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+# Copyright © 2021, 2022, 2023, 2024 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 # Copyright © 2022 Prafulla Giri <prafulla.giri@protonmail.com>
 # Copyright © 2023 Andrew Tropin <andrew@trop.in>
 # Copyright © 2020 David A. Redick <david.a.redick@gmail.com>
@@ -31,10 +31,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
-
-# We require Bash but for portability we'd rather not use /bin/bash or
-# /usr/bin/env in the shebang, hence this hack.
-
+#
+#
 # Environment variables
 #
 # GUIX_BINARY_FILE_NAME
@@ -50,11 +48,6 @@
 # installation required the user to extract Guix packs under /gnu to
 # satisfy its dependencies.
 
-if [ "x$BASH_VERSION" = "x" ]
-then
-    exec bash "$0" "$@"
-fi
-
 set -eo pipefail
 
 [ "$UID" -eq 0 ] || { echo "This script must be run as root."; exit 1; }
-- 
2.46.0