More LTO tweaks

Don't use premake's "LinkTimeOptimization" flag on Mac either. This will attempt to use llvm-ar, which doesn't always exist on Mac.

Enable premake's "LinkTimeOptimization" flag on Windows.

Diffs=
e2328daeb More LTO tweaks (#6904)

Co-authored-by: Chris Dalton <99840794+csmartdalton@users.noreply.github.com>

.rive_head

diff --git a/.rive_head b/.rive_head
index 46970fa..6f9ea6f 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-cae08a3c5612afad5077dcd6008b73b33fa3c938
+e2328daeb02a92171cd3c0ab78c3c76695a9dd98

build/rive_build_config.lua

diff --git a/build/rive_build_config.lua b/build/rive_build_config.lua
index 1e97ca1..25f9c3d 100644
--- a/build/rive_build_config.lua
+++ b/build/rive_build_config.lua
@@ -113,14 +113,14 @@
     optimize('On')
 end
 
-filter({ 'options:config=release', 'options:not no-lto', 'not system:ios or windows' })
+filter({ 'options:config=release', 'options:not no-lto', 'system:not macosx', 'system:not ios'})
 do
     flags({ 'LinkTimeOptimization' })
 end
 
--- The 'LinkTimeOptimization' premake flag generates errors when building for ios.
-filter({ 'options:config=release', 'options:not no-lto', 'system:ios' })
+filter({ 'options:config=release', 'options:not no-lto', 'system:macosx or ios' })
 do
+    -- The 'LinkTimeOptimization' flag attempts to use llvm-ar, which doesn't always exist on macos.
     buildoptions({ '-flto=full' })
     linkoptions({ '-flto=full' })
 end