docs: Update license related comments

[Xuanwo]

Read discussion at https://lists.apache.org/thread/299jvgkcj1opppg89mwl9nnfd1cwqv1y for more details.

We need to

• Fix the comment for https://github.com/apache/incubator-opendal/blob/a8ae017877d38a4362099eab6380d8f54fa4ab6f/core/src/raw/http_util/body.rs#L94
  • Use Inspired instead to avoid confusing.
• Fix the comment for https://github.com/apache/incubator-opendal/blob/a8ae017877d38a4362099eab6380d8f54fa4ab6f/core/src/services/memcached/backend.rs#L275
  • Remove this out-dated comments

[Prashanth-Chandra]

@Xuanwo can you assign me to this issue?

[Xuanwo]

Thanks a lot!

[Prashanth-Chandra]

I have made the changes and created the Pull Request

[Xuanwo]

Fixed by #2573, thank @Prashanth-Chandra!