support Dash as /bin/sh

[JtMotoX]

I am using Dash for /bin/sh and the Asahi installer fails with "Your version of cURL is too old". This is because the curl check uses &>/dev/null which Dash does not support. Updating to use the more compatible >/dev/null 2>&1 instead.

> curl https://alx.sh | sh
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2289  100  2289    0     0   4364      0 --:--:-- --:--:-- --:--:--  4368
Your version of cURL is too old. This usually means your macOS is very out
of date. Installing Asahi Linux requires at least macOS version 13.5.

> sw_vers
ProductName:		macOS
ProductVersion:		15.1.1
BuildVersion:		24B91

> what /bin/sh
/bin/sh:
	PROGRAM:sh  PROJECT:dash-16
	PROGRAM:sh  PROJECT:dash-16

> /bin/sh -c 'if ! date &>&1; then echo "something wrong"; else echo "something right"; fi'
something wrong
Fri Nov 29 14:21:27 PST 2024

> /bin/sh -c 'if ! date >/dev/null 2>&1; then echo "something wrong"; else echo "something right"; fi'
something right