chore(bindings/python): Add Justfile and format codebase

[chitralverma]

Which issue does this PR close?

Parts from #6622

Rationale for this change

Partially Closes #6253

What changes are included in this PR?

• Adds Justfile
• Formats everything as per ruff rules (some rules are temporarily added and will be removed post stubs)
  • No functional change
• Update Readme and Contributing guides as per the new Justfile
• Update CI workflow to rely on justfile

Are there any user-facing changes?

No, just better dev experience and code formatting.
No breaking changes are introduced.

[Xuanwo]

Thank you for working on this, but the change set is too complex to me.

[chitralverma]

Thank you for working on this, but the change set is too complex to me.

most of the changes are a result of linting and formatting from ruff.

the tests and the benchmarks pass as usual.
No functional change is introduced.

[Xuanwo]

Thank you for working on this! I’d really like us to start with a simple, clean Justfile containing only the essential steps. I don’t want to maintain one cluttered with commands I never use.

[chitralverma]

@Xuanwo i've dropped some unnecessary changes (removed "RUF", # ruff-specific rules) from this PR in addition to your comments.
ready for your review, whenever you've time/

[Xuanwo]

Thank you for working on this!