Fix ava + .ts for node 20

See avajs/ava#2593 (comment)

This fixes:

```
./node_modules/.bin/ava

(node:605416) ExperimentalWarning: Custom ESM Loaders is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
  Uncaught exception in tests/session_test.ts

  TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for code/websites/cards/tests/session_test.ts

  ✘ tests/session_test.ts exited with a non-zero exit code: 1
  ─

  1 uncaught exception
```

package.json

@@ -5,7 +5,7 @@
 		"dev": "vite dev",
 		"build": "vite build",
 		"preview": "vite preview",
-		"test": "./node_modules/.bin/ava && ./node_modules/.bin/tsc --target esnext --moduleResolution node --noEmit tests/*.ts && ./node_modules/.bin/eslint .",
+		"test": "NODE_OPTIONS='--loader=tsx' ./node_modules/.bin/ava && ./node_modules/.bin/tsc --target esnext --moduleResolution node --noEmit tests/*.ts && ./node_modules/.bin/eslint .",
 		"check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
 		"lint": "prettier --plugin-search-dir . --check . && eslint .",
@@ -55,8 +55,7 @@
 	"ava": {
 		"extensions": {
 			"ts": "module"
-		},
-		"nodeArguments": ["--loader=tsx"]
+		}
 	},
 	"pnpm": {
 		"overrides": {