refactor: convert providers to be installed via package

currently providers have a `pip_package` list. Rather than make our own form of python dependency management, we should use `pyproject.toml` files in each provider declaring the dependencies in a more trackable manner.
Each provider can then be installed using the already in place `module` field in the ProviderSpec, pointing to the directory the provider lives in
we can then simply `uv pip install` this directory as opposed to installing the dependencies one by one

Signed-off-by: Charlie Doern <cdoern@redhat.com>

llama_stack/providers/remote/inference/azure/pyproject.toml

@@ -0,0 +1,18 @@
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "llama-stack-provider-inference-azure"
+version = "0.1.0"
+description = "Azure OpenAI inference provider for accessing GPT models and other Azure services. Provider documentation https://learn.microsoft.com/en-us/azure/ai-foundry/openai/overview"
+authors = [{ name = "Meta Llama", email = "llama-oss@meta.com" }]
+requires-python = ">=3.12"
+license = { "text" = "MIT" }
+dependencies = [
+    "litellm",
+]
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["llama_stack*"]