Update NEWS.md for VortexStepMethod v2.2.1 #915

Job	Run time
Julia 1.11 - ubuntu-latest - x64 - with code coverage	6m 45s
Julia pre - ubuntu-latest - x64 - with code coverage	5m 28s
Julia 1.10 - ubuntu-latest - x64 - with code coverage	8m 42s
Julia 1 - macOS-latest - aarch64 - push	6m 20s
Julia 1 - windows-latest - x64 - push	13m 27s
Julia 1.10 - ubuntu-latest - x64 - push	8m 53s
Julia 1 - ubuntu-latest - x64 - push	11m 14s
Documentation	6m 16s
	1h 7m 5s

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