[webgpu] Bump version of Dawn to b9b4a370 (#23494)
### Description
This PR updates the version of Dawn to
`b9b4a37041dec3dd62ac92014a6cc1aece48d9f3` (ref:
[chromium](https://chromium.googlesource.com/chromium/src.git/+/67f86f01ddb0e5cbdac4a050c17c468deb740c6c/DEPS#399))
in the `deps.txt` file.
The newer version of Dawn includes the previous changes from dawn.patch
so that we can remove the patch file.
There is a little interface changes and code is updated correspondingly.
