Remove invalid extra commas from json data (#6176)

Ensure all json files pass the following validation

$ git ls-files "*.json" |
    while read f; do python -m json.tool $f >/dev/null || echo $f; done

asv.conf.json

@@ -14,5 +14,5 @@
     "env_dir": ".asv/env",
     "results_dir": ".asv/results",
     "html_dir": ".asv/html",
-    "hash_length": 8,
+    "hash_length": 8
 }

cirq-web/cirq_ts/tsconfig.json

@@ -11,9 +11,9 @@
     "downlevelIteration": true,
     "declaration": false,
     "sourceMap": false,
-    "outDir": "build",
+    "outDir": "build"
   },
   "include": [
-    "src/**/*.ts",
-  ],
+    "src/**/*.ts"
+  ]
 }