Update issensitive.mdx - Fixed function name typo (#36723)

Fixed a typo in the examples section where the example using a variable as an argument was calling `sensitive()` instead of `issensitive()`.

website/docs/language/functions/issensitive.mdx

@@ -22,6 +22,6 @@ See [`sensitive`](/terraform/language/functions/sensitive), [`nonsensitive`](/te
 true
 > issensitive("hello")
 false
-> sensitive(var.my-var-with-sensitive-set-to-true)
+> issensitive(var.my-var-with-sensitive-set-to-true)
 true
 ```