chore(docs): format Friedland Chapter 8 notebook with ruff (#1341)

[priyam0k]

Summary of Changes

• Formatted docs/friedland/chapter_8.ipynb using ruff format to maintain consistent formatting across all Friedland notebooks.

Related GitHub Issue(s)

• Fixes [CHORE] format Friedland Chapter 8 notebook with ruff #1341

Additional Context for Reviewers

All pre-commit ruff checks pass cleanly and all notebook cells run and pass locally.

Checklist

• I passed tests locally for both code (uv run pytest) and documentation changes (uv run --directory docs jb build . --builder=custom --custom-builder=doctest)

---

Note

Low Risk
Documentation-only notebook formatting with no application or library code changes.

Overview
Applies ruff format to docs/friedland/chapter_8.ipynb so Chapter 8 matches the formatting style used for the other Friedland documentation notebooks. This is a style-only change to notebook code cells (whitespace, line breaks, quoting); exhibit logic and reconciliation asserts are unchanged.

Fixes #1341.

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[github-actions]

Pyright Type Completeness

View the full pyright --verifytypes output for this commit

Project (full chainladder package, at this PR's head): 15.1% of exported symbols fully typed (208 / 1380)

	Known	Ambiguous	Unknown	Total
Project (head)	208	111	1061	1380

Other symbols referenced but not exported by chainladder: 13

	Known	Ambiguous	Unknown	Total
Other (head)	3	1	9	13

Symbols without documentation:

• Functions without docstring: 327
• Functions without default param: 0
• Classes without docstring: 10

Patch (exported symbols added or changed by this PR): no exported symbol type-completeness changes detected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.76%. Comparing base (d7479a4) to head (5e044a5).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1344   +/-   ##
=======================================
  Coverage   91.76%   91.76%           
=======================================
  Files          96       96           
  Lines        5475     5475           
  Branches      706      706           
=======================================
  Hits         5024     5024           
  Misses        327      327           
  Partials      124      124           

Flag	Coverage Δ
unittests	91.76% <ø> (ø)

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[henrydingliu]

assigning to @kennethshsu as he OG'd chapter 8