[pdal] fix pthreads on linux + check for pdal >= 2.2 (#40619)

cmake/FindPDAL.cmake

@@ -67,6 +67,13 @@ IF (PDAL_FOUND)
       MESSAGE(STATUS "Found PDAL: ${PDAL_LIBRARIES} (${PDAL_VERSION})")
    ENDIF (NOT PDAL_FIND_QUIETLY)
 
+   IF (PDAL_VERSION_MAJOR LESS 2)
+      MESSAGE (FATAL_ERROR "PDAL version is too old (${PDAL_VERSION}). Use 2.2 or higher.")
+   ENDIF()
+   IF ( (PDAL_VERSION_MAJOR EQUAL 2) AND (PDAL_VERSION_MINOR LESS 2) )
+      MESSAGE (FATAL_ERROR "PDAL version is too old (${PDAL_VERSION}). Use 2.2 or higher.")
+   ENDIF()
+
 ELSE (PDAL_FOUND)
    IF (PDAL_FIND_REQUIRED)
      MESSAGE(FATAL_ERROR "Could not find PDAL")

src/providers/pdal/CMakeLists.txt

@@ -1,6 +1,8 @@
 ########################################################
 # Files
 
+
+set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
 set(PDAL_SRCS
@@ -119,13 +121,14 @@ set_target_properties(untwine PROPERTIES
 
 target_link_libraries (untwine
   ${PDAL_LIBRARIES}
+  Threads::Threads
 )
 target_include_directories(untwine PRIVATE ${UNTWINE_INCLUDE_DIRS})
 
 add_library (pdalprovider MODULE ${PDAL_SRCS} ${PDAL_HDRS} ${PDAL_GUI_SRCS} ${PDAL_GUI_HDRS})
 target_link_libraries (pdalprovider
   ${PDAL_LIBRARIES}
-  ${CMAKE_THREAD_LIBS_INIT}
+  Threads::Threads
 )
 
 if (WITH_GUI)