Fix llama stack build in 0.0.54 (#505)

# What does this PR do?

Safety provider `inline::meta-reference` is now deprecated. However, we 

* aren't checking / printing the deprecation message in `llama stack
build`
* make the deprecated (unusable) provider

So I (1) added checking and (2) made `inline::llama-guard` the default

## Test Plan

Before

```
Traceback (most recent call last):
  File "/home/dalton/.conda/envs/nov22/bin/llama", line 8, in <module>
    sys.exit(main())
  File "/home/dalton/all/llama-stack/llama_stack/cli/llama.py", line 46, in main
    parser.run(args)
  File "/home/dalton/all/llama-stack/llama_stack/cli/llama.py", line 40, in run
    args.func(args)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 177, in _run_stack_build_command
    self._run_stack_build_command_from_build_config(build_config)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 305, in _run_stack_build_command_from_build_config
    self._generate_run_config(build_config, build_dir)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 226, in _generate_run_config
    config_type = instantiate_class_type(
  File "/home/dalton/all/llama-stack/llama_stack/distribution/utils/dynamic.py", line 12, in instantiate_class_type
    module = importlib.import_module(module_name)
  File "/home/dalton/.conda/envs/nov22/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1004, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'llama_stack.providers.inline.safety.meta_reference'
```

After

```
Traceback (most recent call last):
  File "/home/dalton/.conda/envs/nov22/bin/llama", line 8, in <module>
    sys.exit(main())
  File "/home/dalton/all/llama-stack/llama_stack/cli/llama.py", line 46, in main
    parser.run(args)
  File "/home/dalton/all/llama-stack/llama_stack/cli/llama.py", line 40, in run
    args.func(args)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 177, in _run_stack_build_command
    self._run_stack_build_command_from_build_config(build_config)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 309, in _run_stack_build_command_from_build_config
    self._generate_run_config(build_config, build_dir)
  File "/home/dalton/all/llama-stack/llama_stack/cli/stack/build.py", line 228, in _generate_run_config
    raise InvalidProviderError(p.deprecation_error)
llama_stack.distribution.resolver.InvalidProviderError: 
Provider `inline::meta-reference` for API `safety` does not work with the latest Llama Stack.
- if you are using Llama Guard v3, please use the `inline::llama-guard` provider instead.
- if you are using Prompt Guard, please use the `inline::prompt-guard` provider instead.
- if you are using Code Scanner, please use the `inline::code-scanner` provider instead.
```

<img width="469" alt="Screenshot 2024-11-22 at 4 10 24 PM"
src="https://github.com/user-attachments/assets/8c2e09fe-379a-4504-b246-7925f80a6ed6">

## Sources

Please link relevant resources if necessary.


## Before submitting

- [ ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [x] Ran pre-commit to handle lint / formatting issues.
- [ ] Read the [contributor
guideline](https://github.com/meta-llama/llama-stack/blob/main/CONTRIBUTING.md),
      Pull Request section?
- [ ] Updated relevant documentation.
- [ ] Wrote necessary unit or integration tests.

llama_stack/providers/registry/safety.py

@@ -17,6 +17,16 @@ from llama_stack.distribution.datatypes import (
 
 def available_providers() -> List[ProviderSpec]:
     return [
+        InlineProviderSpec(
+            api=Api.safety,
+            provider_type="inline::prompt-guard",
+            pip_packages=[
+                "transformers",
+                "torch --index-url https://download.pytorch.org/whl/cpu",
+            ],
+            module="llama_stack.providers.inline.safety.prompt_guard",
+            config_class="llama_stack.providers.inline.safety.prompt_guard.PromptGuardConfig",
+        ),
         InlineProviderSpec(
             api=Api.safety,
             provider_type="inline::meta-reference",
@@ -48,16 +58,6 @@ Provider `inline::meta-reference` for API `safety` does not work with the latest
                 Api.inference,
             ],
         ),
-        InlineProviderSpec(
-            api=Api.safety,
-            provider_type="inline::prompt-guard",
-            pip_packages=[
-                "transformers",
-                "torch --index-url https://download.pytorch.org/whl/cpu",
-            ],
-            module="llama_stack.providers.inline.safety.prompt_guard",
-            config_class="llama_stack.providers.inline.safety.prompt_guard.PromptGuardConfig",
-        ),
         InlineProviderSpec(
             api=Api.safety,
             provider_type="inline::code-scanner",