docs: Add new term entry for Hierarchical Inheritance in Python

[Prankisster]

Description

This PR adds a new term entry under the Inheritance section in Python: Hierarchical Inheritance. The new file is located at: content/python/concepts/inheritance/terms/hierarchical-inheritance/hierarchical-inheritance.md

Issue Solved

Closes #7081

Type of Change

• [x] Adding a new entry

Checklist

• [x] All writings are my own.
• [x] My entry follows the Codecademy Docs style guide.
• [x] My changes generate no new warnings.
• [x] I have performed a self-review of my own writing and code.
• [x] I have checked my entry and corrected any misspellings.
• [x] I have made corresponding changes to the documentation if needed.
• [x] I have confirmed my changes are not being pushed from my forked main branch.
• [x] I have confirmed that I'm pushing from a new branch named after the changes I'm making.
• [x] I have linked any issues that are relevant to this PR in the Issues Solved section.