fix(cmake): link CMAKE_DL_LIBS after libarrow.a to fix gcc8 fs_test link

libarrow.a calls dlsym but the arrow imported target did not declare
${CMAKE_DL_LIBS} in its link interface, so -ldl could end up before
libarrow.a in the final link line. Linkers that resolve symbols strictly
left-to-right (gcc8-test in CI) then fail linking paimon-fs-test with
"undefined reference to dlsym / DSO missing from command line" once
fs_test started linking the jindo static libraries. Declare
${CMAKE_DL_LIBS} on the arrow interface, matching the lucene and
jindosdk::nextarch targets.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: 子懿

cmake_modules/ThirdpartyToolchain.cmake

@@ -1636,13 +1636,16 @@ macro(build_arrow)
 
     target_link_libraries(arrow_dataset INTERFACE arrow_acero)
 
+    # libarrow.a calls dlsym; keep ${CMAKE_DL_LIBS} in the interface so -ldl is placed
+    # after libarrow.a on linkers that resolve symbols strictly left-to-right.
     target_link_libraries(arrow
                           INTERFACE zstd
                                     snappy
                                     lz4
                                     zlib
                                     re2::re2
-                                    arrow_bundled_dependencies)
+                                    arrow_bundled_dependencies
+                                    ${CMAKE_DL_LIBS})
 
     target_link_libraries(parquet
                           INTERFACE zstd