Fix update version awk shebang

[romain-grecourt]

Use

#!/usr/bin/env -S awk -f

Instead of:

#!/usr/bin/env awk -f

Otherwise the following error occurs on Linux:

/usr/bin/env: use -[v]S to pass options in shebang lines

This is a difference between BSD and Linux, using -S works on both.

| The -S/--split-string option enables use of multiple arguments on the first line of scripts (the shebang line, ‘#!’).

See https://www.gnu.org/software/coreutils/manual/html_node/env-invocation.html