Patch autoconf-archive with an updated variant of `AX_C_FLOAT_WORDS_BIGENDIAN`

[erlend-aasland]

Background:

• configure script cannot detect float word ordering on linux cpython#89640
• AX_C_FLOAT_WORDS_BIGENDIAN: Fix bug "AX_C_FLOAT_WORDS_BIGENDIAN fails… autoconf-archive/autoconf-archive#279
• configure script cannot detect float word ordering on linux cpython#89640 (comment)

There has been no new release of autoconf-archive with Dan Amelang's fix in it. We could cherry-pick his fix and include it in our autoconf image. What do you think, @corona10? It would resolve python/cpython#89640.