tools/gnulib: update to branch stable-202407

tools/gnulib: update to branch stable-202407

Bump to the next stable branch with the May 2025 update.

Add a patch to compensate for gnulib-tool being further split up
into independent shell and python implementations
by using a non-hidden version of the main.py file.

Add a patch for the python implementation of gnulib-tool
in order to ignore the required version of autoconf in configure.ac
being lower than the required version of autoconf for gnulib
if the version that is being run exceeds the required version for both,
and adjust existing autoconf version shell script patch to new filename.

Backport a patch for a change in function naming convention
for forward compatibility with tool releases after this stable branch.

Added:
 - 020-python-version.patch
 - 021-python-main.patch
 - 500-acl-function-name.patch

Manually Adjusted:
 - 010-autoconf-version.patch
 - 160-flag-reallocarray.patch

Existing patches are automatically refreshed.

Signed-off-by: Michael Pratt <mcpratt@pm.me>
Link: https://github.com/openwrt/openwrt/pull/16522
Signed-off-by: Robert Marko <robimarko@gmail.com>