Use devel/readline instead of readline in the base system.

Index: cmake/FindReadline.cmake
--- cmake/FindReadline.cmake.orig
+++ cmake/FindReadline.cmake
@@ -22,19 +22,19 @@
 #  LIBEDIT_LIBRARY           The libedit library or empty string.
 
 find_path(Readline_ROOT_DIR
-    NAMES include/readline/readline.h
+    NAMES include/ereadline/readline/readline.h
     PATHS /usr/local/opt/readline/ /opt/homebrew/opt/readline/ /opt/local/ /usr/local/ /usr/
     NO_DEFAULT_PATH
 )
 
 find_path(Readline_INCLUDE_DIR
     NAMES readline/readline.h
-    PATHS ${Readline_ROOT_DIR}/include
+    PATHS ${Readline_ROOT_DIR}/include/ereadline
     NO_DEFAULT_PATH
 )
 
 find_library(Readline_LIBRARY
-    NAMES readline
+    NAMES ereadline
     PATHS ${Readline_ROOT_DIR}/lib
     NO_DEFAULT_PATH
 )
