Timeline (barchart) view does not cap off at 1h, but extends to 2h.

- [x] I am on the [latest](https://github.com/ActivityWatch/activitywatch/releases/latest) ActivityWatch version.
- [x] I have searched the issues of this repo and believe that this is not a duplicate.

- **Ubuntu 20.04 LTS 5.15.0-60-generic**:
- **ActivityWatch version v0.12.1**:

## Describe the bug

The Timeline (barchart) view does not cap off at 1h, but extends to 2h.

## To Reproduce

Go to Activity tab, work for over an hour, and observe

## Expected behavior

barchart should cap at 1h

## Documentation


## Additional context