sys-apps/systemd: add v256.5 with musl libc patches

- https://code.atwilcox.tech/sphen/scaly/systemd
- https://catfox.life/2024/09/05/porting-systemd-to-musl-libc-powered-linux/

sys-apps/systemd/files/0034-build-path-Disable-for-now.patch

@@ -0,0 +1,35 @@
+From 5cfb7905b38ca0e537b93403a7ef577bc3b19a82 Mon Sep 17 00:00:00 2001
+From: "A. Wilcox" <AWilcox@Wilcox-Tech.com>
+Date: Sun, 18 Aug 2024 20:23:03 -0500
+Subject: [PATCH 34/34] build-path: Disable for now
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 8bit
+
+Digging for RPATH is broken on musl, and causes segfaults all throughout
+the systemd manager when running.  This means we lose the ability to run
+systemd applets from a build tree, but we can just iterate in our
+virthosts until this can be fixed.
+
+This cannot be upstreamed.
+
+Signed-off-by: Alexander Miroshnichenko <alex@millerson.name>
+---
+ src/basic/build-path.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/basic/build-path.c b/src/basic/build-path.c
+index b5972658dfea..9c4c6233f76b 100644
+--- a/src/basic/build-path.c
++++ b/src/basic/build-path.c
+@@ -157,7 +157,7 @@ int get_build_exec_dir(char **ret) {
+                 runpath_cached = get_runpath(&runpath);
+ 
+                 /* We only care if the runpath starts with $ORIGIN/ */
+-                if (runpath_cached > 0 && !startswith(runpath, "$ORIGIN/"))
++                //if (runpath_cached > 0 && !startswith(runpath, "$ORIGIN/"))
+                         runpath_cached = 0;
+         }
+         if (runpath_cached < 0)
+-- 
+2.41.0
+