CompatHelper: bump compat for SymbolicUtils in [weakdeps] to 2, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the SymbolicUtils package from 0.19, ^1.0.5 to 0.19, ^1.0.5, 2.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[ChrisRackauckas]

Looking at the code, this should just work. Let me know if you have any problems updating.

[MilesCranmer]

Not sure why but it's not actually testing 2:

⌃ [d1185830] SymbolicUtils v1.6.0

Edit: Oh, it's this one: SymbolicML/DynamicExpressions.jl#78

[github-actions]

Benchmark Results

	master	7c2137a...	master/7c2137a153a60b...
search/multithreading	19.2 ± 0.21 s	19.9 ± 0.48 s	0.964
search/serial	33.5 ± 0.94 s	32.8 ± 0.024 s	1.02
utils/best_of_sample	0.792 ± 0.37 μs	0.861 ± 0.29 μs	0.92
utils/check_constraints_x10	11.5 ± 2.9 μs	11.6 ± 3 μs	0.994
utils/compute_complexity_x10/Float64	2.18 ± 0.11 μs	2.33 ± 0.16 μs	0.935
utils/compute_complexity_x10/Int64	2.21 ± 0.11 μs	2.23 ± 0.11 μs	0.987
utils/compute_complexity_x10/nothing	1.47 ± 0.1 μs	1.49 ± 0.091 μs	0.987
utils/optimize_constants_x10	0.032 ± 0.0076 s	31.4 ± 7.1 ms	1.02
time_to_load	0.912 ± 0.0014 s	0.917 ± 0.0098 s	0.994

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).

[MilesCranmer]

(Done)