Update return type annotations in rules.jl

[wsmoses]

cc @kshyatt

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.01%. Comparing base (a7509fb) to head (c627f6a).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2730      +/-   ##
==========================================
- Coverage   70.01%   70.01%   -0.01%     
==========================================
  Files          58       58              
  Lines       19295    19295              
==========================================
- Hits        13510    13509       -1     
- Misses       5785     5786       +1     

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[github-actions]

Benchmark Results

	main	c627f6a...	main / c627f6a...
basics/make_zero/namedtuple	0.0545 ± 0.0029 μs	0.053 ± 0.0022 μs	1.03 ± 0.07
basics/make_zero/struct	0.255 ± 0.0058 μs	0.267 ± 0.0047 μs	0.957 ± 0.027
basics/overhead	4.34 ± 0.02 ns	4.65 ± 1.8 ns	0.933 ± 0.37
basics/remake_zero!/namedtuple	0.239 ± 0.0073 μs	0.239 ± 0.0078 μs	1 ± 0.045
basics/remake_zero!/struct	0.235 ± 0.0093 μs	0.241 ± 0.01 μs	0.975 ± 0.056
fold_broadcast/multidim_sum_bcast/1D	10.3 ± 0.31 μs	10.3 ± 0.28 μs	1 ± 0.041
fold_broadcast/multidim_sum_bcast/2D	12.1 ± 0.29 μs	12.1 ± 0.25 μs	1 ± 0.032
time_to_load	1.27 ± 0.0099 s	1.26 ± 0.015 s	1 ± 0.014

Benchmark Plots

A plot of the benchmark results has been uploaded as an artifact at https://github.com/EnzymeAD/Enzyme.jl/actions/runs/19044759412/artifacts/4452743057.

[giordano]

Docs building is now successful, so it was indeed a scoping issue