libphonenumber: unpin boost, fix build with boost 1.89

Finding `boost_system` fails because the stub compiled library of
Boost.System, which has been a header-only library since 1.69, was
removed in 1.89 [1].

Upstream PR: https://github.com/google/libphonenumber/pull/3903

[1] https://www.boost.org/releases/1.89.0/

pkgs/by-name/li/libphonenumber/boost-1.89.patch

@@ -0,0 +1,22 @@
+From 72c1023fbf00fc48866acab05f6ccebcae7f3213 Mon Sep 17 00:00:00 2001
+From: Michael Cho <michael@michaelcho.dev>
+Date: Mon, 11 Aug 2025 17:08:15 -0400
+Subject: [PATCH] Fix build with Boost 1.89.0
+
+---
+ cpp/CMakeLists.txt | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
+index 27e4680ccc..39f05d2c9a 100644
+--- a/cpp/CMakeLists.txt
++++ b/cpp/CMakeLists.txt
+@@ -145,7 +145,7 @@ if (USE_BOOST)
+   if (WIN32)
+     set (Boost_USE_STATIC_LIBS ON)
+   endif ()
+-  find_package (Boost 1.40.0 COMPONENTS date_time system thread)
++  find_package (Boost 1.40.0 COMPONENTS date_time thread OPTIONAL_COMPONENTS system)
+   if (NOT Boost_FOUND)
+     print_error ("Boost Date_Time/System/Thread" "Boost")
+   endif ()

pkgs/by-name/li/libphonenumber/package.nix

@@ -8,8 +8,7 @@
   gtest,
   jre,
   pkg-config,
-  # complains about missing boost.system on 1.89
-  boost188,
+  boost,
   icu,
   protobuf,
 }:
@@ -31,6 +30,11 @@ stdenv.mkDerivation (finalAttrs: {
     ./build-reproducibility.patch
     # Fix include directory in generated cmake files with split outputs
     ./cmake-include-dir.patch
+    # Finding `boost_system` fails because the stub compiled library of
+    # Boost.System, which has been a header-only library since 1.69, was
+    # removed in 1.89.
+    # Upstream PR: https://github.com/google/libphonenumber/pull/3903
+    ./boost-1.89.patch
   ];
 
   outputs = [
@@ -53,7 +57,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   propagatedBuildInputs = lib.optionals enableTests [
-    boost188
+    boost
   ];
 
   cmakeDir = "../cpp";