package/ghostscript: fix build with host GCC 15

Fix the following autobuild error on configs with host GCC15.

```
/workdir/instance-0/output-1/host/bin/ccache /usr/bin/gcc   -O2 -DNDEBUG -Wall -Wstrict-prototypes -Wundef -Wmissing-declarations -Wmissing-prototypes -Wwrite-strings -fno-strict-aliasing -Werror=declaration-after-statement -fno-builtin -fno-common -Werror=return-type -Wno-unused-local-typedefs -DHAVE_STDINT_H=1 -DHAVE_DIRENT_H=1 -DHAVE_SYS_DIR_H=1 -DHAVE_SYS_TIME_H=1 -DHAVE_SYS_TIMES_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_LIBDL=1 -DGX_COLOR_INDEX_TYPE="unsigned long long" -D__USE_UNIX98=1 -DHAVE_SNPRINTF  -O2 -I/workdir/instance-0/output-1/host/include -L/workdir/instance-0/output-1/host/lib -Wl,-rpath,/workdir/instance-0/output-1/host/lib -DNOCONTRIB -DHAVE_RESTRICT=1 -DHAVE_LIMITS_H=1 -DHAVE_STRING_H=1 -fno-strict-aliasing -O2 -I/workdir/instance-0/output-1/host/include -L/workdir/instance-0/output-1/host/lib -Wl,-rpath,/workdir/instance-0/output-1/host/lib -DHAVE_POPEN_PROTO=1  -I./base -o ./obj/aux/genconf ./base/genconf.c   -lz
In file included from ./base/genconf.c:18:
./base/stdpre.h:348:13: error: 'bool' cannot be defined via 'typedef'
  348 | typedef int bool;
      |             ^~~~
./base/stdpre.h:348:13: note: 'bool' is a keyword with '-std=c23' onwards
./base/stdpre.h:348:1: warning: useless type name in empty declaration
  348 | typedef int bool;
      | ^~~~~~~
```

This is due to the change in the default C language version in GCC15.

The patch included is not exactly the same as the upstream one, it only
picks the part that fix the `bool` definition and dropped the declaration
type changes.

Fixes: https://autobuild.buildroot.org/results/9c6/9c6cbff256635c6ab4be4c5b7bf18f9d3c4b46681

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/ghostscript/0001-Fix-compatibility-with-C23-compilers.patch

@@ -0,0 +1,36 @@
+From ae940946473ceb8c5353bc6e7f04673c6e60502d Mon Sep 17 00:00:00 2001
+From: Alex Cherepanov <alex@coscript.biz>
+Date: Thu, 3 Apr 2025 17:19:41 +0100
+Subject: Bug 708160: Fix compatibility with C23 compilers
+
+Upstream: https://cgit.ghostscript.com/cgi-bin/cgit.cgi/ghostpdl.git/commit/?id=ae940946473ceb8c5353bc6e7f04673c6e60502d
+[thomas: Only backport the bool typedef condition]
+Signed-off-by: Thomas Perale <thomas.perale@mind.be>
+---
+ base/stdpre.h              |  6 ++++--
+ 1 files changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/base/stdpre.h b/base/stdpre.h
+index dda30b6a4..2f9c84e0d 100644
+--- a/base/stdpre.h
++++ b/base/stdpre.h
+@@ -1,4 +1,4 @@
+-/* Copyright (C) 2001-2023 Artifex Software, Inc.
++/* Copyright (C) 2001-2025 Artifex Software, Inc.
+    All Rights Reserved.
+
+    This software is provided AS-IS with no warranty, either express or
+@@ -341,7 +341,9 @@ typedef signed char schar;
+  * and the MetroWerks C++ compiler insists that bool be equivalent to
+  * unsigned char.
+  */
+-#ifndef __cplusplus
++
++/* C23 has bool as a builtin type. */
++#if !defined(__cplusplus) && (!defined(__STDC_VERSION__) || __STDC_VERSION__ < 202311L)
+ #ifdef __BEOS__
+ typedef unsigned char bool;
+ #else
+--
+cgit v1.2.3
+