fix copyright year

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017-2018 U.S. Federal Government (in countries where recognized)
+Copyright (c) 2023 U.S. Federal Government (in countries where recognized)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this
 software and associated documentation files (the "Software"), to deal in the Software
@@ -17,4 +17,4 @@ INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
-OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.