meta: Enable '-o pipefail' for the SDK installer

meta: Enable '-o pipefail' for the SDK installer

When testing a Yocto SDK installer on Alpine 3.21, we recently ended up with a
broken SDK. One of the commands the relocation script calls in a piped
multi-command chain failed (see [0]), but the installer did not realize that -
since it doesn't use 'set -o pipefail'. Thus, the error was never reported to
the user and the installer claimed to have set up the SDK correctly - which
wasn't the case.

Given that the SDK installer is a POSIX-compliant shell script and that the
'pipefail' option used to be missing from the standard, it's not surprising that
it isn't used. Thankfully however, in June of 2024, a new version of POSIX
(POSIX.1-2024) was released - and that one finally includes the 'pipefail'
option (see [1]). A number of shells already support it, so let's enable it if
available to make the SDK installer more robust.

The change has been tested locally using SDK installers for internal projects,
based on both Kirkstone and Scarthgap.

[0]: https://gitlab.alpinelinux.org/alpine/aports/-/issues/16797
[1]: https://pubs.opengroup.org/onlinepubs/9799919799.2024edition/utilities/V3_chap02.html#set

Signed-off-by: Moritz Haase <Moritz.Haase@bmw.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>