fix: rename llama_stack_api dir (#4155)

# What does this PR do?

the directory structure was src/llama-stack-api/llama_stack_api

instead it should just be src/llama_stack_api to match the other
packages.

update the structure and pyproject/linting config

---------

Signed-off-by: Charlie Doern <cdoern@redhat.com>
Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

src/llama-stack-api/llama_stack_api/common/tracing.py

@@ -1,22 +0,0 @@
-# Copyright (c) Meta Platforms, Inc. and affiliates.
-# All rights reserved.
-#
-# This source code is licensed under the terms described in the LICENSE file in
-# the root directory of this source tree.
-
-
-def telemetry_traceable(cls):
-    """
-    Mark a protocol for automatic tracing when telemetry is enabled.
-
-    This is a metadata-only decorator with no dependencies on core.
-    Actual tracing is applied by core routers at runtime if telemetry is enabled.
-
-    Usage:
-        @runtime_checkable
-        @telemetry_traceable
-        class MyProtocol(Protocol):
-            ...
-    """
-    cls.__marked_for_tracing__ = True
-    return cls