feat: Add git based bundling strategy

[chrismcg]

Allow for specifying a bundlingStrategy as part of the bundling params. If this is BundlingStrategy.SOURCE then do the same as before. If it's BundlingStrategy.GIT then use git command output to decide if the package needs rebuilt or not.

 new PythonFunction(stack, 'workspaces_app', {
      rootDir: path.join(rootPath, 'workspaces_app'),
      workspacePackage: 'app',
      index: 'app_handler.py',
      handler: 'handle_event',
      runtime: Runtime.PYTHON_3_10,
      architecture: await getDockerHostArch(),
      bundling: {
        bundlingStrategy: BundlingStrategy.GIT,
      },
    });

If we're not using a package in a workspace app then use the last commit hash for the entire rootDir and anything in git diff to generate the custom hash for CDK bundling.

If we are using a package in a workspace app then get the list of dependencies and check and local ones for changes. This uses the hash of the last commit and any git diff in that part of the tree for each dependency and the package itself.

As this involved editing files in the project the tests add some helper functions to clone the workspace to a temporary directory and do the edits there.

This PR originally had the PACKAGE_VERSION bundling strategy but it's been removed as the tests couldn't be made to pass because of something uv related so lower confidence it would work in practise.