Build: Add macOS x64 deprecation warning to make update

Add a simple deprecation message to warn users that macOS pre-compiled
dependencies are no longer provided starting with 5.0, and that they
should either build the libraries themselves or downgrade to 4.5.

This is what the warning looks like in context:
```
$ make update
git lfs install --skip-repo
Git LFS initialized.

Configuring Precompiled Libraries
=================================

Detected platform     : macos
Detected architecture : x64

Updating Libraries
==================

* Skipping lib/linux_x64
* Skipping lib/macos_arm64
* Skipping lib/windows_x64
* Skipping lib/windows_arm64

Update finished with the following messages
===========================================

Blender repository skipped: you have unstaged changes
WARNING: macOS x64/Intel support was dropped in Blender 5.0.
         As such, pre-compiled dependencies are no longer provided.
         You may build the dependencies yourself, or downgrade to Blender 4.5.
         For more details, please see: https://devtalk.blender.org/t/38835
```

Pull Request: https://projects.blender.org/blender/blender/pulls/143133

build_files/utils/make_update.py

@@ -227,6 +227,12 @@ def initialize_precompiled_libraries(args: argparse.Namespace) -> str:
 
     submodule_directories = get_submodule_directories(args)
 
+    if platform == "macos" and arch == "x64":
+        return ("WARNING: macOS x64/Intel support was dropped in Blender 5.0.\n"
+                "         As such, pre-compiled dependencies are no longer provided.\n"
+                "         You may build the dependencies yourself, or downgrade to Blender 4.5.\n"
+                "         For more details, please see: https://devtalk.blender.org/t/38835")
+
     if Path(submodule_dir) not in submodule_directories:
         return "Skipping libraries update: no configured submodule\n"