[js/web] remove "types" from "exports" field in package.json (#23733)
### Description
<!-- Describe your changes. -->
Remove unused "types" field from "exports" field in package.json
### Motivation and Context
#23639 introduces update of esbuild. The new version warns about the
"types" field in the "exports" field in package.json.
```
The condition "types" here will never be used as it comes after both "import" and "require" [package.json]
web/package.json:77:6:
77 │ "types": "./types.d.ts"
╵ ~~~~~~~
```