v8.15.0

ModelingToolkit v8.15.0

Diff since v8.14.1

Closed issues:

• ModelingToolkit.unwrap() dropped? (#1651)
• Updating packages changed the system efficiency (#1664)

Merged pull requests:

• Strengthen alias elimination (#1635) (@Keno)
• Add pretty-printing for BipartiteGraph (#1657) (@Keno)
• Constraints and expression handling in OptimizationProblem (#1660) (@Vaibhavdixit02)
• Cleanup callbacks (#1661) (@isaacsas)
• upper bound Symbolics to 4.7.0 (#1662) (@shashi)
• Add observed equation to SDEfunction (#1665) (@frankschae)
• remove ControlSystem (#1667) (@ChrisRackauckas)
• Revert "upper bound Symbolics to 4.7.0" (#1669) (@shashi)
• Support parameter dict in modelingtoolkitize (#1671) (@YingboMa)
• Remove Requires.jl usage (#1672) (@ChrisRackauckas)
• Rename DiffEqJump to JumpProcesses (#1674) (@isaacsas)