Bump version to 2.3.0

[ChrisRackauckas-Claude]

Version Bump

Bumping version from 2.2.0 to 2.3.0 to prepare for release.

Changes since last release (v2.2.0)

• CompatHelper: bump compat for JET in [extras] to 0.11
• CompatHelper: bump compat for ModelingToolkit to 11
• Bump actions/checkout from 4 to 6
• Cleanup and test dependencies consolidation
• Add scalar dispatch for SymbolicNeuralNetwork (PR Add scalar dispatch for SymbolicNeuralNetwork (fixes #83) #84)

Registration Command

After merging, register with:

@JuliaRegistrator register

cc @ChrisRackauckas

🤖 Generated with Claude Code

[JuliaRegistrator]

Error while trying to register: Register Failed
@ChrisRackauckas-Claude, it looks like you are not a publicly listed member/owner in the parent organization (SciML).
If you are a member/owner, you will need to change your membership to public. See GitHub Help