v6.39.0

OrdinaryDiffEq v6.39.0

Diff since v6.37.0

Closed issues:

• New Runge-Kutta-Nyström method of Tsitouras and Simon (#1495)
• More stage/step limiters and threaded broadcasting (in explicit RK methods) (#1511)
• Trapezoid docstring (#1838)

Merged pull requests:

• Implement DPRKN5 method (#1831) (@ErikQQY)
• Add ERKN7 method (#1832) (@ErikQQY)
• Add more optional threading (#1833) (@ErikQQY)
• fix ode_determine_initdt for zero-length arrays (#1834) (@ranocha)
• Remove unnecessary branches of Vern7, Vern9 and Tsit5 (#1835) (@ErikQQY)
• Add docs for optional threading (#1837) (@ErikQQY)
• [skip ci] spelling (#1839) (@ArnoStrouwen)
• Add DPRKN4 method (#1840) (@ErikQQY)
• Add DPRKN6FM method (#1841) (@ErikQQY)
• max methods 1, a couple stability fixes (#1845) (@chriselrod)