Merge bitcoin#34572: cmake: Fix NetBSD-specific workaround for Boost

79c934b cmake: Fix NetBSD-specific workaround for Boost (Hennadii Stepanov)

Pull request description:

  The recently merged bitcoin#34143 broke builds with depends on NetBSD due to a workaround introduced in 5a5ddbd.

  The upstream [bug](https://gnats.netbsd.org/59856) has been fixed, and the entire workaround can be removed once the fixed Boost package becomes generally available.

  However, it seems prudent to amend the workaround now to have it workable in the 31.0 release.

  Here are CI runs:
  - broken: https://github.com/hebasto/bitcoin-core-nightly/actions/runs/21933683654
  - fixed: https://github.com/hebasto/bitcoin-core-nightly/actions/runs/21933683654

ACKs for top commit:
  fanquake:
    ACK 79c934b

Tree-SHA512: 360e4943fbedc7692fa2eba48f3375fc927d3aaef178dec6c0fafd3addfad0c89db9d1fe88e214313ebd285584bf8dc7d7b0a3a41d905c7f3d28293aa743405a

Author: fanquake

cmake/module/AddBoostIfNeeded.cmake

@@ -32,12 +32,14 @@ function(add_boost_if_needed)
   find_package(Boost 1.74.0 REQUIRED CONFIG)
   mark_as_advanced(Boost_INCLUDE_DIR boost_headers_DIR)
   # Workaround for a bug in NetBSD pkgsrc.
-  # See: https://github.com/NetBSD/pkgsrc/issues/167.
+  # See https://gnats.netbsd.org/59856.
   if(CMAKE_SYSTEM_NAME STREQUAL "NetBSD")
     get_filename_component(_boost_include_dir "${boost_headers_DIR}/../../../include/" ABSOLUTE)
-    set_target_properties(Boost::headers PROPERTIES
-      INTERFACE_INCLUDE_DIRECTORIES ${_boost_include_dir}
-    )
+    if(_boost_include_dir MATCHES "^/usr/pkg/")
+      set_target_properties(Boost::headers PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES ${_boost_include_dir}
+      )
+    endif()
     unset(_boost_include_dir)
   endif()
   set_target_properties(Boost::headers PROPERTIES IMPORTED_GLOBAL TRUE)