⬆️ Upgrade HTTPX & Requests

[roma-glushko]

Description

Upgrading the client dependencies that have gotten a bit stale.

Changes

• Updated httpx to 0.28.* version. Had to bump Python to >=3.8 at least to install the newer version of httpx
• Updated requests to pull in the latest version without CVEs (also reported by dependabot in https://github.com/GearPlug/bitbucket-python/pull/14)
• Pinned httpx & requests in a way that allows to pull the latest minor version updates
• Ignored the IDE directories

[roma-glushko]

Hey @alejomjc 👋 Happy new year!

Would accept this dependency update? I would really like to use this client but cannot really install it because it pins pretty old versions of httpx & requests.