Fix(Gantt): skipped exclusion of last saturday

[artur-michalak]

Description

If the excluded Saturday is the last day on the gantt chart, the last column will not change color.

Steps to reproduce

1. open the mermaid playground
2. paste snippet
3. no highlighting of the last column

Screenshots

Code Sample

gantt
    dateFormat YYYY-MM-DD
    excludes saturday, sunday
    tickInterval 1day
    section  
        A:active,2016-01-11,2016-01-15
        B:2016-01-17,2016-01-24

Setup

• Mermaid version: v10.9.1
• Browser and Version: Chrome

Suggested Solutions

No response

Additional Context

No response