build: remove -flto-partition=none

As reported in
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/1714,
it was added to workaround a bug in GCC. That bug was fixed long ago
thus this option is no longer needed. Moreover, it increases the memory
usage during the build and we are geting some failures when building in
ppc64 systems that we suspect are due to memory exhaustion.

Fixes https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/1714

contrib/fedora/rpm/NetworkManager.spec

@@ -164,11 +164,6 @@
 %global ebpf_enabled "no"
 %endif
 
-# Fedora 33 enables LTO by default by setting CFLAGS="-flto -ffat-lto-objects".
-# However, we also require "-flto -flto-partition=none", so disable Fedora's
-# default and use our configure option --with-lto instead.
-%define _lto_cflags %{nil}
-
 ###############################################################################
 
 Name: NetworkManager

meson.build

@@ -172,19 +172,11 @@ if enable_ld_gc
 endif
 
 enable_lto = get_option('b_lto')
-if enable_lto
-  if  cc.get_id() == 'clang'
+if enable_lto and cc.get_id() == 'clang'
   clang_version = cc.version()
   if clang_version <= '18.0.0'
     error('Clang version should be greater then 18.0.0 got : ' + clang_version)
   endif
-  else
-    # Meson already adds '-flto'
-    lto_flag = '-flto-partition=none'
-    assert(cc.has_argument(lto_flag), '-flto-partition=none not supported. Disable link-time optimization with -Db_lto=false.')
-    common_flags += lto_flag
-    common_ldflags += lto_flag
-  endif
 endif
 
 common_flags += cc.get_supported_arguments([