delete old failing test

test/validator/samples/binding-this-invalid-foreign-namespace /errors.json

@@ -1,15 +0,0 @@
-[{
-	"code": "invalid-binding",
-	"message": "'this' is not a valid binding. Foreign elements only support bind:this",
-	"pos": 81,
-	"start": {
-		"line": 6,
-		"column": 7,
-		"character": 81
-	},
-	"end": {
-		"line": 6,
-		"column": 27,
-		"character": 101
-	}
-}]

test/validator/samples/binding-this-invalid-foreign-namespace /input.svelte

@@ -1,6 +0,0 @@
-<svelte:options namespace="foreign" />
-<script>
-	let whatever;
-</script>
-
-<input bind:this={whatever} />