package/tstools: fix build w/ gcc-15

GCC-15 defaults to C23, which changes the meaning of an empty parameter
list:

https://gcc.gnu.org/gcc-15/porting_to.html#c23-fn-decls-without-parameters

Leading to a build failure:

tsserve.c: In function ‘set_child_exit_handler’:
tsserve.c:2988:21: error: assignment to ‘__sighandler_t’ {aka ‘void (*)(int)’} from incompatible pointer type ‘void (*)(void)’ [-Wincompatible-pointer-types]
 2988 |   action.sa_handler = on_child_exit;

Add a patch from an upstream PR to fix that.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tstools/0002-fix-build-with-gcc-15.patch

@@ -0,0 +1,27 @@
+From a1f2a71b286135d89865bb0332cbe3db59cea300 Mon Sep 17 00:00:00 2001
+From: Rudi Heitbaum <rudi@heitbaum.com>
+Date: Mon, 9 Dec 2024 16:57:53 +1100
+Subject: [PATCH] fix build with gcc-15
+
+Upstream: https://github.com/kynesim/tstools/pull/44
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ tsserve.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tsserve.c b/tsserve.c
+index d81042e..253ba0c 100644
+--- a/tsserve.c
++++ b/tsserve.c
+@@ -2958,7 +2958,7 @@ static void set_child_exit_handler();
+ /*
+  * Signal handler - catch children and stop them becoming zombies
+  */
+-static void on_child_exit()
++static void on_child_exit(int signum)
+ {
+ #if 0
+   print_msg("sighandler: starting\n");
+-- 
+2.39.5
+