[openwrt/openwrt] tools: gnulib: always use std-gnu23 module

[LEDE Commits]

robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/a808086826a75976947fc38ad0c58b20e398f7b9

commit a808086826a75976947fc38ad0c58b20e398f7b9
Author: Michael Pratt <mcpratt at pm.me>
AuthorDate: Fri Aug 8 00:58:56 2025 -0400

    tools: gnulib: always use std-gnu23 module
    
    The new "std-gnu23" module has the stated goal of:
    "...to update the c99 module to depend on std-gnu23
    instead of on std-gnu11, and to make std-gnu11 obsolete."
    in upstream commit 8990abb50 ("std-gnu23: new module").
    
    However, for now, it's design is optional, so that
    definitions of the latest standard module overrides the former.
    At some point, upstream gnulib will replace the dependency
    instead of add it alongside the older one.
    
    Because all macros are copied to the aclocal directory,
    for complex projects, not including the module
    may cause the macros to apply only to some subdirectories
    rather than all of them and top-level together.
    
    For projects that import source from local gnulib,
    always include the std-gnu23.m4 macros for consistency.
    
    Signed-off-by: Michael Pratt <mcpratt at pm.me>
    Link: https://github.com/openwrt/openwrt/pull/19748
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 tools/gnulib/patches/195-c99-use-std-gnu23.patch | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/gnulib/patches/195-c99-use-std-gnu23.patch b/tools/gnulib/patches/195-c99-use-std-gnu23.patch
new file mode 100644
index 0000000000..11c2f3297c
--- /dev/null
+++ b/tools/gnulib/patches/195-c99-use-std-gnu23.patch
@@ -0,0 +1,10 @@
+--- a/modules/c99
++++ b/modules/c99
+@@ -5,6 +5,7 @@ Files:
+ 
+ Depends-on:
+ std-gnu11
++std-gnu23
+ 
+ configure.ac:
+