It doesn't build without it, it then tries to use a generated spawn
header and fails with something like:
```
CC gl_linkedhash_list.o
In file included from /home/builder/.termux-build/m4/src/lib/execute.c:72:
./spawn.h:690:17: error: use of undeclared identifier 'POSIX_SPAWN_RESETIDS'
[(((POSIX_SPAWN_RESETIDS | POSIX_SPAWN_SETPGROUP
^
./spawn.h:690:40 CC gl_list.o
: error: use of undeclared identifier 'POSIX_SPAWN_SETPGROUP'
[(((POSIX_SPAWN_RESETIDS | POSIX_SPAWN_SETPGROUP
^
./spawn.h:691:19: error: use of undeclared identifier 'POSIX_SPAWN_SETSIGDEF'
| POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK
^
```
Solve this error by depending on libandroid-spawn instead.
In issue https://github.com/termux/termux-packages/issues/6160 I have found
that community repo "its-pointless.github.io" specifies us as maintainer
for its packages. This is NOT TRUE and potentially misleads people using
these packages.
Now TERMUX_PKG_MAINTAINER will contain a default value which is neutral
and not specify maintainer. So all packages now have to override it to
the correct value.
[skip ci]
%ci:no-build
The old version of gnulib that m4 uses tries to use the %n printf
modifier which aborts the process on Android 10 onwards.
Fixes#4381 (thanks easyaspi314).
