CompatHelper: bump compat for "Zygote" to "0.6" for package test (#211)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: David Widmann <[email protected]>

Author: github-actions[bot]

Project.toml

@@ -1,6 +1,6 @@
 name = "KernelFunctions"
 uuid = "ec8451be-7e33-11e9-00cf-bbf324bd1392"
-version = "0.8.20"
+version = "0.8.21"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"

test/Project.toml

@@ -27,4 +27,4 @@ Kronecker = "0.4"
 PDMats = "0.9, 0.10"
 ReverseDiff = "1.2"
 SpecialFunctions = "0.10, 1"
-Zygote = "0.4, 0.5"
+Zygote = "0.4, 0.5, 0.6"