ci: add test job to lint workflow and update deno.json

Add test script to deno.json
Add @std/assert, @std/testing, happy-dom dependencies

deno.json

@@ -9,7 +9,8 @@
     "start": "deno run -A --unstable-ffi --watch=static/,routes/ dev.ts",
     "build": "deno run -A --unstable-ffi dev.ts build",
     "preview": "deno run -A --unstable-ffi main.ts",
-    "update": "deno run -A -r https://fresh.deno.dev/update ."
+    "update": "deno run -A -r https://fresh.deno.dev/update .",
+    "test": "deno test -A --no-check tests/"
   },
   "lint": {
     "rules": {
@@ -35,6 +36,9 @@
     "@preact/signals": "https://esm.sh/*@preact/signals@1.2.2",
     "@preact/signals-core": "https://esm.sh/*@preact/signals-core@1.5.1",
     "$std/": "https://deno.land/std@0.216.0/",
+    "@std/assert": "jsr:@std/assert@^1.0.0",
+    "@std/testing": "jsr:@std/testing@^1.0.0",
+    "happy-dom": "npm:happy-dom@^16.0.0",
     "$root/": "./",
     "$apps/": "./routes/(apps)/"
   },