bug#49930: glibc-2.34 build failure in gnulib (needs a sync)

Hi bug-guile!

Recent glibc-2.34 released changed attribute macros slightly
which broke older gnulib macros. Fixed in gnulib upstream as:
    https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=0c907f7da13232908f05c415b8cec56024071906

guile.git now fails to build on x86_64-linux as:

```
  CC       regex.lo
In file included from regexec.c:1368,
                 from regex.c:74:
./malloc/dynarray-skeleton.c:195:24: error: expected declaration specifiers or '...' before '(' token
  195 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:205:51: error: expected declaration specifiers or '...' before '(' token
  205 | __attribute_maybe_unused__ __attribute_nonnull__ ((1))
      |                                                   ^
./malloc/dynarray-skeleton.c:216:24: error: expected declaration specifiers or '...' before '(' token
  216 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:225:24: error: expected declaration specifiers or '...' before '(' token
  225 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:239:24: error: expected declaration specifiers or '...' before '(' token
  239 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:248:24: error: expected declaration specifiers or '...' before '(' token
  248 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:260:24: error: expected declaration specifiers or '...' before '(' token
  260 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c:270:24: error: expected declaration specifiers or '...' before '(' token
  270 | __attribute_nonnull__ ((1))
      |                        ^
./malloc/dynarray-skeleton.c: In func
```

Would it be reasonable to sync gnulib and cut a guile point release
compatible with it?

Thank you!

-- 

  Sergei