[tz] Building tz with gcc-13

[Todd C. Miller]

On Sat, 11 Mar 2023 11:18:43 +0100, Martin Jansa via tz wrote:

> I was building tz with gcc-13 and noticed that without explicit -std=c2x it
> fails to build 2022g version with:
> ```
> zic.c:462:1: warning: ‘noreturn’ attribute ignored [-Wattributes]
>   462 | static ATTRIBUTE_NORETURN void
>       | ^~~~~~
> zic.c:462:27: error: expected identifier or ‘(’ before ‘void’
>   462 | static ATTRIBUTE_NORETURN void
>       |                           ^~~~
> ```

Try swapping the order of ATTRIBUTE_NORETURN and "static".  C23
attributes are supposed to come first (unlike gcc-style attributes)
similar to C++.

 - todd