Remove `now.json` from examples (#8057)

examples/dynamic-routing/now.json

-{
-  "version": 2,
-  "builds": [{ "src": "package.json", "use": "@now/next@canary" }]
-}

examples/with-graphql-hooks/.nowignore

-node_modules
\ No newline at end of file

examples/with-graphql-hooks/now.json

-{
-  "version": 2,
-  "name": "next-with-graphql-hooks",
-  "builds": [{ "src": "next.config.js", "use": "@now/next" }]
-}

examples/with-react-multi-carousel/now.json

-{
-  "version": 2,
-  "name": "nextjs",
-  "builds": [{ "src": "package.json", "use": "@now/next" }]
-}

examples/with-semantic-ui/now.json

-{
-  "version": 2,
-  "name": "with-semantic-ui",
-  "builds": [{ "src": "package.json", "use": "@now/next" }]
-}