fix: Fix copying symlink files for Windows

[hnnasit]

Which issue(s) does this change fix?

#6943

Note: Adding an integration test seemed like an overkill for a small change. I've added unit tests to cover these, but lmk if you feel adding one is necessary.

Why is this change necessary?

When the shared (within same code_uri) node_module dependencies were copied over to the other Function, the symlink files were not being copied over. However, as mentioned in the docs, copy2 does not copy symlinks on all the platforms (Windows being 1 of them). This causes OsError to be thrown crashing the command.

How does it address the issue?

Catches the exception and handles it by calling create_symlink_or_copy function to either create a symlink or copy the target file directly.

What side effects does this change have?

No side effects.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.