Be explicit with igraph's cmake flags

Author: DavidRConnell

CMakeLists.txt

@@ -9,6 +9,14 @@ find_package(
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
+set(IGRAPH_ENABLE_LTO AUTO)
+set(IGRAPH_USE_INTERNAL_GMP ON)
+set(IGRAPH_USE_INTERNAL_ARPACK ON)
+set(IGRAPH_USE_INTERNAL_BLAS ON)
+set(IGRAPH_USE_INTERNAL_GLPK ON)
+set(IGRAPH_USE_INTERNAL_LAPACK ON)
+set(IGRAPH_USE_INTERNAL_PLFIT ON)
+
 add_subdirectory(vendor/speakeasy2)
 
 if(NOT "${SKBUILD_SABI_VERSION}" STREQUAL "")