build(test): run unit tests with vitest and jsdom

Karma needed headless Chrome. Vitest with jsdom runs with no browser.
Lighthouse CI now gets Chrome from @puppeteer/browsers.
Two CSS font tests are dropped: jsdom does not apply real CSS.

tsconfig.spec.json

@@ -5,7 +5,7 @@
   "compilerOptions": {
     "outDir": "./out-tsc/spec",
     "types": [
-      "jasmine",
+      "vitest/globals",
       "@webgpu/types"
     ]
   },