v1.21.0

SciMLBase v1.21.0

Diff since v1.20.0

Closed issues:

• Compat chart link warning is missing (#123)

Merged pull requests:

• Make some setup calls easier (#122) (@ChrisRackauckas)
• Fix warning kwargs (#124) (@ChrisRackauckas)
• Move callback definitions to SciMLBase (#125) (@ChrisRackauckas)