Add compat downgrade YAML

[xlxs4]

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the ScioML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Ref. SciML/SciMLBase.jl#553

[github-actions]

Benchmark Results

	master	0621c05...	t[master]/t[0621c05...]
Simple Pendulum/IIP/MultipleShooting(10, Tsit5; grid_coarsening = false)	1.84 ± 0.056 ms	1.83 ± 0.053 ms	1.01
Simple Pendulum/IIP/MultipleShooting(10, Tsit5; grid_coarsening = true)	3.42 ± 0.1 ms	3.38 ± 0.088 ms	1.01
Simple Pendulum/IIP/MultipleShooting(100, Tsit5; grid_coarsening = false)	0.0537 ± 0.0039 s	0.053 ± 0.0039 s	1.01
Simple Pendulum/IIP/MultipleShooting(100, Tsit5; grid_coarsening = true)	1.15 ± 0.015 s	1.1 ± 0.0062 s	1.05
Simple Pendulum/IIP/Shooting(Tsit5())	0.181 ± 0.006 ms	0.178 ± 0.0052 ms	1.02
Simple Pendulum/OOP/MultipleShooting(10, Tsit5; grid_coarsening = false)	4.3 ± 0.31 ms	4.16 ± 0.21 ms	1.03
Simple Pendulum/OOP/MultipleShooting(10, Tsit5; grid_coarsening = true)	7.58 ± 4.5 ms	7.55 ± 4.5 ms	1
Simple Pendulum/OOP/MultipleShooting(100, Tsit5; grid_coarsening = false)	0.135 ± 0.0036 s	0.126 ± 0.0022 s	1.07
Simple Pendulum/OOP/MultipleShooting(100, Tsit5; grid_coarsening = true)	4.85 ± 0.046 s	4.69 ± 0.015 s	1.03
Simple Pendulum/OOP/Shooting(Tsit5())	0.726 ± 0.039 ms	0.707 ± 0.035 ms	1.03
time_to_load	7.97 ± 0.03 s	7.96 ± 0.072 s	1

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).