Test with TypeScript 5.9 (#189)

Fixes #188. Tests pass locally for me.

Author: domoritz

tests/ts5.9/package.json

@@ -0,0 +1,9 @@
+{
+  "scripts": {
+    "test": "tsc --version && tsc"
+  },
+  "dependencies": {
+    "@webgpu/types": "file:../..",
+    "typescript": "~5.9.0"
+  }
+}

tests/ts5.9/tsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "../tsconfig.json",
+  "include": ["../index.ts"]
+}