fix: enforce stricter ASCII rules lint rules in Ruff (#2062)

# What does this PR do?

- Added new Ruff lint rules to detect ambiguous or non-ASCII characters:
- Added per-file ignores where Unicode usage is still required.
- Fixed whatever had to be fixed

Signed-off-by: Sébastien Han <seb@redhat.com>

llama_stack/cli/stack/run.py

@@ -119,7 +119,7 @@ class StackRun(Subcommand):
 
         if not config_file.is_file():
             self.parser.error(
-                f"Config file must be a valid file path, '{config_file}’ is not a file: type={type(config_file)}"
+                f"Config file must be a valid file path, '{config_file}' is not a file: type={type(config_file)}"
             )
 
         logger.info(f"Using run configuration: {config_file}")

llama_stack/distribution/build.py

@@ -47,14 +47,13 @@ def get_provider_dependencies(
         providers = config.distribution_spec.providers
     deps = []
     registry = get_provider_registry(config)
-
     for api_str, provider_or_providers in providers.items():
         providers_for_api = registry[Api(api_str)]
 
         providers = provider_or_providers if isinstance(provider_or_providers, list) else [provider_or_providers]
 
         for provider in providers:
-            # Providers from BuildConfig and RunConfig are subtly different – not great
+            # Providers from BuildConfig and RunConfig are subtly different - not great
             provider_type = provider if isinstance(provider, str) else provider.provider_type
 
             if provider_type not in providers_for_api: