perf: add dynamically loaded cache-dependencies for actions python

This reduces the main bundle size by ⚠️  1.28 MB minified! This bundle is loaded only when caching is enabled.

`setup-python` is used in [`setup-cpp`](https://github.com/aminya/setup-cpp) as a library. This optimization reduces the bundle size for that package as well. The build system of `setup-python` uses `ncc`, which doesn't immediately benefit from this change, but setup-cpp uses `Parcel`, which shows this huge improvement.

The reason for this huge reduction is that caching the dependencies uses the `@actions/cache` package, which is an extremely large package with big dependencies. The bundle size before this separation shows this:
![Screenshot_20230907_230625](https://github.com/actions/setup-python/assets/16418197/ec1baf34-85c3-459d-b8cf-894899959b2c)

Author: aminya