core/zip: do not use file globbing

core/zip/CMakeLists.txt

 find_package(ZLIB REQUIRED)
 
-ROOT_GLOB_HEADERS(headers
-  inc/Compression.h
-  inc/RZip.h
-)
-
-ROOT_GLOB_SOURCES(sources
+ROOT_OBJECT_LIBRARY(Zip
   src/Bits.c
   src/ZDeflate.c
   src/ZTrees.c
@@ -14,7 +9,6 @@ ROOT_GLOB_SOURCES(sources
   src/RZip.cxx
 )
 
-ROOT_OBJECT_LIBRARY(Zip ${sources})
 target_include_directories(Zip PRIVATE ${ZLIB_INCLUDE_DIR})
 
 ROOT_INSTALL_HEADERS()