Enforce NetworkX 3.4

[f-allian]

Quick fix to #327

[github-actions]

🦙 MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ PYTHON	black	31		0	0.96s
✅ PYTHON	pylint	31		0	6.06s

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.69%. Comparing base (fcab481) to head (a940927).
Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #328   +/-   ##
=======================================
  Coverage   95.69%   95.69%           
=======================================
  Files          27       27           
  Lines        1602     1603    +1     
=======================================
+ Hits         1533     1534    +1     
  Misses         69       69           

Files with missing lines	Coverage Δ
causal_testing/testing/causal_test_case.py	100.00% <100.00%> (ø)

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[jmafoster1]

I modified the assertions a bit on the tests so that the test case is actually run. I realised that the formula parameter wasn't actually a valid estimate parameter for estimate_ate, so wanted to test the parameters were actually getting used properly.