Use uv build backend for changelog tool

This changes the build backend for the changelog tool to uv,
which is what we're using to manage the project anyway. The
project was also renamed to `smithy_changelog` to be more
explicit, and the module name was also renamed.

Author: JordonPhillips

.changes/amend

@@ -1,7 +1,7 @@
 #! /usr/bin/env python3
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
-from tool.amend import main
+from smithy_changelog.amend import main
 
 
 if __name__ == "__main__":

.changes/new-change

@@ -1,7 +1,7 @@
 #! /usr/bin/env python3
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
-from tool.new import main
+from smithy_changelog.new import main
 
 
 if __name__ == "__main__":

.changes/pyproject.toml

@@ -1,15 +1,15 @@
 [project]
-name = "changelog"
+name = "smithy_changelog"
 version = "0.1.0"
 description = "A staged changelog tool for Smithy."
 readme = "README.md"
 requires-python = ">=3.12"
 dependencies = []
 
 [project.scripts]
-amend = "tool.amend:main"
-render = "tool.render:main"
-new-change = "tool.new:main"
+amend = "smithy_changelog.amend:main"
+render = "smithy_changelog.render:main"
+new-change = "smithy_changelog.new:main"
 
 [dependency-groups]
 lint = [
@@ -20,6 +20,13 @@ typing = [
     "pyright>=1.1.403"
 ]
 
+[build-system]
+requires = ["uv_build>=0.8.2,<0.9.0"]
+build-backend = "uv_build"
+
+[tool.uv.build-backend]
+module-root = ""
+
 [tool.uv]
 package = true
 required-version = ">=0.7.21"

.changes/render

@@ -1,7 +1,7 @@
 #! /usr/bin/env python3
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
-from tool.render import main
+from smithy_changelog.render import main
 
 
 if __name__ == "__main__":