bootc: fix rustc 1.90.0 errors

Upstream has `-D dead_code`, and since rustc 1.90 more dead code got
detected in the tree, so this upstream patch fixes that. ff8b1b4112.patch

Alternative: update bootc, but I'd consider this a cleaner ZHF fix than
that.

ZHF: #457852

pkgs/by-name/bo/bootc/package.nix

@@ -2,6 +2,7 @@
   lib,
   rustPlatform,
   fetchFromGitHub,
+  fetchpatch2,
   libz,
   zstd,
   pkg-config,
@@ -25,6 +26,13 @@ rustPlatform.buildRustPackage rec {
     hash = "sha256-TztsiC+DwD9yEAmjTuiuOi+Kf8WEYMsOVVnMKpSM3/g=";
   };
 
+  patches = [
+    (fetchpatch2 {
+      url = "https://github.com/bootc-dev/bootc/commit/ff8b1b411270275c49ee512d54b27ed7a2fca112.patch";
+      hash = "sha256-7UKquq6ZargQUDGZk22X9Co92v8e995bL+tuAjvh/7c=";
+    })
+  ];
+
   nativeBuildInputs = [ pkg-config ];
 
   buildInputs = [