fix test

Author: dummdidumm

packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/import-precedence/expectedv2.json

@@ -1,19 +1 @@
-[
-    {
-        "code": 6263,
-        "message": "Module './c.svelte' was resolved to 'c:/repos/svelte/language-tools/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/import-precedence/c.d.svelte.ts', but '--allowArbitraryExtensions' is not set.",
-        "range": {
-            "end": {
-                "character": 34,
-                "line": 4
-            },
-            "start": {
-                "character": 22,
-                "line": 4
-            }
-        },
-        "severity": 1,
-        "source": "ts",
-        "tags": []
-    }
-]
+[]

packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/import-precedence/tsconfig.json

@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "strict": true,
+        "allowJs": true,
+        "target": "ESNext",
+        /**
+          This is actually not needed, but makes the tests faster
+          because TS does not look up other types.
+        */
+        "types": ["svelte"],
+        "allowArbitraryExtensions": true // else .d.svelte.ts will be an error
+    }
+}