fix: install python stuff only if installed with scikit build

apps/hiopy/CMakeLists.txt

-install(DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
-  COMPONENT python
-  EXCLUDE_FROM_ALL
-  DESTINATION "."
-)
+if( SKBUILD EQUAL 2 )
+  install(DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+    COMPONENT python
+    EXCLUDE_FROM_ALL
+    DESTINATION ${SKBUILD_PLATLIB_DIR}
+    FILES_MATCHING PATTERN "*.py"
+    PATTERN "tests/*" EXCLUDE
+    PATTERN "__pycache__" EXCLUDE
+  )
+endif()
 
 add_subdirectory(tests)

python/CMakeLists.txt

@@ -7,5 +7,7 @@ target_link_libraries(coyote_py PRIVATE coyote)
 target_compile_definitions(coyote_py
   PRIVATE VERSION_INFO=${PROJECT_VERSION})
 
-install(TARGETS coyote LIBRARY COMPONENT python EXCLUDE_FROM_ALL DESTINATION .)
-install(TARGETS coyote_py LIBRARY COMPONENT python EXCLUDE_FROM_ALL DESTINATION .)
+if( SKBUILD EQUAL 2 )
+  install(TARGETS coyote LIBRARY COMPONENT python EXCLUDE_FROM_ALL DESTINATION ${SKBUILD_PLATLIB_DIR})
+  install(TARGETS coyote_py LIBRARY COMPONENT python EXCLUDE_FROM_ALL DESTINATION ${SKBUILD_PLATLIB_DIR})
+endif()

src/CMakeLists.txt

-add_library(coyote coyote.cpp coyoteenv.cpp healpixgrid.cpp)
-target_link_libraries(coyote PUBLIC YAC::YAC Threads::Threads)
+add_library(coyote
+  coyote.cpp coyoteenv.cpp healpixgrid.cpp
+)
+set_target_properties(coyote
+  PROPERTIES
+  PUBLIC_HEADER "coyote.hpp"
+  PRIVATE_HEADER "coyoteenv.hpp;field.hpp;healpixgrid.hpp;tsqueue.hpp"
+)
+
+target_link_libraries(coyote PUBLIC MPI::MPI_CXX YAC::YAC Threads::Threads)
 target_include_directories(coyote PUBLIC
   "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>"
   "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>"
 )
+
 if(healpix_FOUND)
   target_link_libraries(coyote PRIVATE healpix::healpix_cxx)
 endif()
+
+install(TARGETS coyote)