Forward-port and reword the new unevaluatedItems test.

Makes it fit a bit better with its neighbors by using similar language
in the descriptions.

This *precise* case seems uncovered by said neighbors
because none precisely have all of:

    * nested unevaluatedItems
    * no prefixItems
    * cases where unevaluatedItems actually gets used for a scenario

It's possible that in aggregate all the cases that are here already
would catch any bugs this scenario would catch (i.e. it's possible this
is redundant in aggregate) but it's safe enough to add just in case
obviously.

Author: Julian

tests/draft-next/unevaluatedItems.json

@@ -149,7 +149,33 @@
     {
         "description": "unevaluatedItems with nested items",
         "schema": {
-            "type": "array",
+            "unevaluatedItems": {"type": "boolean"},
+            "anyOf": [
+                { "items": {"type": "string"} },
+                true
+            ]
+        },
+        "tests": [
+            {
+                "description": "with only (valid) additional items",
+                "data": [true, false],
+                "valid": true
+            },
+            {
+                "description": "with no additional items",
+                "data": ["yes", "no"],
+                "valid": true
+            },
+            {
+                "description": "with invalid additional item",
+                "data": ["yes", false],
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "unevaluatedItems with nested prefixItems and items",
+        "schema": {
             "allOf": [
                 {
                     "prefixItems": [

tests/draft2019-09/unevaluatedItems.json

@@ -147,31 +147,34 @@
         ]
     },
     {
-        "description": "Single-schema items and unevaluatedItems",
+        "description": "unevaluatedItems with nested items",
         "schema": {
             "unevaluatedItems": {"type": "boolean"},
-            "anyOf": [ { "items": {"type": "string"} }, true ]
+            "anyOf": [
+                { "items": {"type": "string"} },
+                true
+            ]
         },
         "tests": [
             {
-                "description": "unevaluatedItems is applied",
+                "description": "with only (valid) additional items",
                 "data": [true, false],
                 "valid": true
             },
             {
-                "description": "unevaluatedItems isn't applied unnecessarily on items annotation boolean of true",
+                "description": "with no additional items",
                 "data": ["yes", "no"],
                 "valid": true
             },
             {
-                "description": "unevaluatedItems is applied on items annotation boolean false",
+                "description": "with invalid additional item",
                 "data": ["yes", false],
                 "valid": false
             }
         ]
     },
     {
-        "description": "unevaluatedItems with nested additionalItems",
+        "description": "unevaluatedItems with nested items and additionalItems",
         "schema": {
             "type": "array",
             "allOf": [

tests/draft2020-12/unevaluatedItems.json

@@ -149,7 +149,33 @@
     {
         "description": "unevaluatedItems with nested items",
         "schema": {
-            "type": "array",
+            "unevaluatedItems": {"type": "boolean"},
+            "anyOf": [
+                { "items": {"type": "string"} },
+                true
+            ]
+        },
+        "tests": [
+            {
+                "description": "with only (valid) additional items",
+                "data": [true, false],
+                "valid": true
+            },
+            {
+                "description": "with no additional items",
+                "data": ["yes", "no"],
+                "valid": true
+            },
+            {
+                "description": "with invalid additional item",
+                "data": ["yes", false],
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "unevaluatedItems with nested prefixItems and items",
+        "schema": {
             "allOf": [
                 {
                     "prefixItems": [