Relax import assertion key-is-type constraint (#13409)

packages/babel-parser/test/fixtures/experimental/import-assertions/invalid-syntax-import-linebreak-asserts/input.js

@@ -0,0 +1,2 @@
+import "foo"
+assert { type: "json" }

packages/babel-parser/test/fixtures/experimental/import-assertions/invalid-syntax-import-linebreak-asserts/output.json

@@ -0,0 +1,69 @@
+{
+  "type": "File",
+  "start":0,"end":36,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":23}},
+  "errors": [
+    "SyntaxError: Missing semicolon. (2:6)"
+  ],
+  "program": {
+    "type": "Program",
+    "start":0,"end":36,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":23}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ImportDeclaration",
+        "start":0,"end":12,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":12}},
+        "specifiers": [],
+        "source": {
+          "type": "StringLiteral",
+          "start":7,"end":12,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":12}},
+          "extra": {
+            "rawValue": "foo",
+            "raw": "\"foo\""
+          },
+          "value": "foo"
+        },
+        "assertions": []
+      },
+      {
+        "type": "ExpressionStatement",
+        "start":13,"end":19,"loc":{"start":{"line":2,"column":0},"end":{"line":2,"column":6}},
+        "expression": {
+          "type": "Identifier",
+          "start":13,"end":19,"loc":{"start":{"line":2,"column":0},"end":{"line":2,"column":6},"identifierName":"assert"},
+          "name": "assert"
+        }
+      },
+      {
+        "type": "BlockStatement",
+        "start":20,"end":36,"loc":{"start":{"line":2,"column":7},"end":{"line":2,"column":23}},
+        "body": [
+          {
+            "type": "LabeledStatement",
+            "start":22,"end":34,"loc":{"start":{"line":2,"column":9},"end":{"line":2,"column":21}},
+            "body": {
+              "type": "ExpressionStatement",
+              "start":28,"end":34,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":21}},
+              "expression": {
+                "type": "StringLiteral",
+                "start":28,"end":34,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":21}},
+                "extra": {
+                  "rawValue": "json",
+                  "raw": "\"json\""
+                },
+                "value": "json"
+              }
+            },
+            "label": {
+              "type": "Identifier",
+              "start":22,"end":26,"loc":{"start":{"line":2,"column":9},"end":{"line":2,"column":13},"identifierName":"type"},
+              "name": "type"
+            }
+          }
+        ],
+        "directives": []
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/experimental/import-assertions/string-literal/output.json

@@ -1,10 +1,6 @@
 {
   "type": "File",
   "start":0,"end":101,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":52}},
-  "errors": [
-    "SyntaxError: The only accepted module attribute is `type`. (1:36)",
-    "SyntaxError: The only accepted module attribute is `type`. (2:40)"
-  ],
   "program": {
     "type": "Program",
     "start":0,"end":101,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":52}},

packages/babel-parser/test/fixtures/experimental/import-assertions/valid-syntax-export-with-no-type-attribute/output.json

@@ -1,9 +1,6 @@
 {
   "type": "File",
   "start":0,"end":55,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":55}},
-  "errors": [
-    "SyntaxError: The only accepted module attribute is `type`. (1:40)"
-  ],
   "program": {
     "type": "Program",
     "start":0,"end":55,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":55}},

packages/babel-parser/test/fixtures/experimental/import-assertions/valid-syntax-export-with-object-method-attribute/output.json

@@ -1,9 +1,6 @@
 {
   "type": "File",
   "start":0,"end":79,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":79}},
-  "errors": [
-    "SyntaxError: The only accepted module attribute is `type`. (1:54)"
-  ],
   "program": {
     "type": "Program",
     "start":0,"end":79,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":79}},

packages/babel-parser/test/fixtures/experimental/import-assertions/valid-syntax-with-no-type-attribute/output.json

@@ -1,9 +1,6 @@
 {
   "type": "File",
   "start":0,"end":51,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":51}},
-  "errors": [
-    "SyntaxError: The only accepted module attribute is `type`. (1:36)"
-  ],
   "program": {
     "type": "Program",
     "start":0,"end":51,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":51}},

packages/babel-parser/test/fixtures/experimental/import-assertions/valid-syntax-with-object-method-attribute/output.json

@@ -1,9 +1,6 @@
 {
   "type": "File",
   "start":0,"end":75,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":75}},
-  "errors": [
-    "SyntaxError: The only accepted module attribute is `type`. (1:50)"
-  ],
   "program": {
     "type": "Program",
     "start":0,"end":75,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":75}},