fix comparison op JVP returning bool tangents instead of input dtype

[mm65x]

Proposed changes

#3081

the six comparison op JVP implementations (Equal, Greater, GreaterEqual,
Less, LessEqual, NotEqual) return zeros(shape, bool_, stream()),
producing bool-typed tangents. this causes downstream ops like negative to
crash with [negative] Not supported for bool, use logical_not instead.

the fix changes them to zeros(shape, tangents[0].dtype(), stream()) so the
zero tangent preserves the input tangent's dtype. this matches the pattern
used by LogicalNot::jvp which already uses zeros_like(tangents[0]).

Checklist

• I have read the CONTRIBUTING document
• I have run pre-commit run --all-files to format my code / installed pre-commit prior to committing changes
• I have added tests that prove my fix is effective or that my feature works
• I have updated the necessary documentation (if needed)

[angeloskath]

Looks good thanks!

[mm65x]

fixed the failing test, was calling an invalid op on the primal path.