deps/soem/1.4: Disable warning stringop-overflow being treated as error

Fixes

Consolidate compiler generated dependencies of target soem
[  5%] Building C object CMakeFiles/soem.dir/oshw/linux/oshw.c.o
In file included from /usr/include/string.h:495,
                 from /home/rkartmann/rt-redesign/deps/soem/1.4/oshw/linux/oshw.c:12:
In function ‘strncpy’,
    inlined from ‘oshw_find_adapters’ at /home/rkartmann/rt-redesign/deps/soem/1.4/oshw/linux/oshw.c:83:11:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: error: ‘__builtin___strncpy_chk’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/rkartmann/rt-redesign/deps/soem/1.4/oshw/linux/oshw.c: In function ‘oshw_find_adapters’:
/home/rkartmann/rt-redesign/deps/soem/1.4/oshw/linux/oshw.c:78:24: note: length computed here
   78 |           string_len = strlen(ids[i].if_name);
      |                        ^~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [CMakeFiles/soem.dir/build.make:230: CMakeFiles/soem.dir/oshw/linux/oshw.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:136: CMakeFiles/soem.dir/all] Error 2
make: *** [Makefile:136: all] Error 2