docs: fix badges in README

[AstreaTSS]

What type of pull request is this?

• Non-breaking code change
• Breaking code change
• Documentation change/addition
• Tests change
• CI change
• Other: [Replace with a description]

Description

Fixes the badges in the README so they don't show badges/shields#8671 anymore. Also adjusts the Black formatting badge to be the pre-commit badge.

Changes

• Use the new format for workflow badges as noted in Change to GitHub workflow badge routes badges/shields#8671.
• Replace the outdated Black formatting badge with the pre-commit workflow badges, since pre-commit replaced it.

Test Scenario(s)

N/A

Checklist

• I've formatted my code with Black
• I've added docstrings to everything I've touched
• I've ensured my code works on Python 3.10.x
• I've ensured my code works on Python 3.11.x
• I've tested my changes
• I've added tests for my code - if applicable
• I've updated the documentation - if applicable