[ITensors] Update KrylovKit compat upper bound to v0.8 (#196)

Author: mofeing

Project.toml

@@ -66,7 +66,7 @@ ITensorMPS = "0.2.2"
 ITensors = "0.6.8"
 IsApprox = "0.1"
 IterTools = "1.4.0"
-KrylovKit = "0.6, 0.7"
+KrylovKit = "0.6, 0.7, 0.8"
 MacroTools = "0.5"
 NDTensors = "0.3"
 NamedGraphs = "0.6.0"