Remove deprecated OpenLDAP support

build/unix/makepchinput.py

cmake/modules/FindLdap.cmake

cmake/modules/RootBuildOptions.cmake

cmake/modules/RootConfiguration.cmake

cmake/modules/SearchInstalledSoftware.cmake

cmake/modules/SetUpMacOS.cmake

config/Makefile.in

documentation/doxygen/Doxyfile

net/CMakeLists.txt

net/ldap/CMakeLists.txt

net/ldap/inc/CintLDAP.h

net/ldap/inc/LinkDef.h

net/ldap/inc/TLDAPAttribute.h

net/ldap/inc/TLDAPEntry.h

net/ldap/inc/TLDAPResult.h

net/ldap/inc/TLDAPServer.h

net/ldap/src/TLDAPAttribute.cxx

net/ldap/src/TLDAPEntry.cxx

net/ldap/src/TLDAPResult.cxx

net/ldap/src/TLDAPServer.cxx