Get loss_function_expression working on distributed workers

[MilesCranmer]

No description provided.

[github-actions]

Benchmark Results

	master	4eedbfe...	master/4eedbfea9429ec...
search/multithreading	16.9 ± 0.16 s	16.1 ± 0.55 s	1.05
search/serial	29 ± 0.13 s	29 ± 0.31 s	0.999
utils/best_of_sample	1.66 ± 0.72 μs	1.63 ± 0.8 μs	1.02
utils/check_constraints_x10	12.1 ± 3.3 μs	12.3 ± 3.4 μs	0.985
utils/compute_complexity_x10/Float64	2.18 ± 0.22 μs	2.15 ± 0.21 μs	1.01
utils/compute_complexity_x10/Int64	2.09 ± 0.21 μs	2.11 ± 0.22 μs	0.991
utils/compute_complexity_x10/nothing	1.49 ± 0.2 μs	1.49 ± 0.21 μs	1
utils/insert_random_op_x10	5.93 ± 2.2 μs	5.96 ± 2.2 μs	0.995
utils/next_generation_x100	0.411 ± 0.067 ms	0.421 ± 0.087 ms	0.977
utils/optimize_constants_x10	0.0365 ± 0.0095 s	0.0355 ± 0.008 s	1.03
utils/randomly_rotate_tree_x10	5.31 ± 0.64 μs	5.4 ± 0.7 μs	0.983
time_to_load	1.95 ± 0.012 s	1.96 ± 0.011 s	0.99

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).

[coveralls]

Pull Request Test Coverage Report for Build 13229894542

Details

• 6 of 6 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.008%) to 95.101%

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Totals
Change from base Build 13218993368:	0.008%
Covered Lines:	3397
Relevant Lines:	3572

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💛 - Coveralls