cmake/modules/FindBoost: add support for Boost 1.88.0

Add Boost 1.88.0 to the supported versions list and update component
dependencies to eliminate build warnings.

This resolves the following warning when building with Boost 1.88.0:

```
-- Found Boost: /usr/include (found suitable version "1.88.0", minimum required is "1.73.0")
CMake Warning at cmake/modules/FindBoost.cmake:1413 (message):
  New Boost version may have incorrect or missing dependencies and imported
  targets
Call Stack (most recent call first):
  cmake/modules/FindBoost.cmake:1538 (_Boost_COMPONENT_DEPENDENCIES)
  cmake/modules/FindBoost.cmake:2157 (_Boost_MISSING_DEPENDENCIES)
  src/CMakeLists.txt:461 (_find_package)
  src/seastar/cmake/SeastarDependencies.cmake:136 (find_package)
  src/seastar/CMakeLists.txt:395 (seastar_find_dependencies)
```

Boost 1.88.0 was released on April 3, 2025, and is already available
in some distributions. Since many distributions don't yet ship Boost's
native CMake configuration files, our vendored FindBoost.cmake module
needs updating to handle this version.

The component dependencies were updated following the scanning procedure
documented in the _Boost_COMPONENT_DEPENDENCIES() function. The change
will be upstreamed to CMake shortly.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/cmake/modules/FindBoost.cmake b/cmake/modules/FindBoost.cmake
index d0a8dda9ccf7034e9ac399efce247730ed7eb591..631ebcaaa668dc0958c6c686871d1f9504e89f28 100644 (file)
--- a/cmake/modules/FindBoost.cmake
+++ b/cmake/modules/FindBoost.cmake
@@ -1425,10 +1425,11 @@ function(_Boost_COMPONENT_DEPENDENCIES component _ret)
       set(_Boost_MPI_DEPENDENCIES serialization)
       set(_Boost_MPI_PYTHON_DEPENDENCIES python${component_python_version} mpi serialization)
       set(_Boost_NUMPY_DEPENDENCIES python${component_python_version})
+      set(_Boost_PROCESS_DEPENDENCIES filesystem)
       set(_Boost_THREAD_DEPENDENCIES chrono atomic)
       set(_Boost_WAVE_DEPENDENCIES filesystem serialization thread chrono atomic)
       set(_Boost_WSERIALIZATION_DEPENDENCIES serialization)
-      if(Boost_VERSION_STRING VERSION_GREATER_EQUAL 1.88.0 AND NOT Boost_NO_WARN_NEW_VERSIONS)
+      if(Boost_VERSION_STRING VERSION_GREATER_EQUAL 1.89.0 AND NOT Boost_NO_WARN_NEW_VERSIONS)
         message(WARNING "New Boost version may have incorrect or missing dependencies and imported targets")
       endif()
     endif()