[Bug]: Backup configuration doesn't trim trailing white space

[mac-chaffee]

Problem description

When trying to set up Deno KV backups to Google Cloud Storage, Google's interface for generating access tokens includes a single trailing space at the end of the access key:

When pasting this into Deno, it can be easy to miss this trailing white space, resulting in the backup failing.

Steps to reproduce

1. Set up a backup configuration for Deno KV
2. Add a trailing whitepsace to the access key
3. Observe the backup fails

Expected behavior

Forms that accept copy/pasted tokens should trim leading and trailing white space.

Environment

No response

Possible solution

No response

Additional context

No response