Fixed dimming incomplete past tasks in widgets (#203)

[Aga-C]

What is it?

• [x] Bugfix
• [ ] Feature
• [ ] Codebase improvement

Description of the changes in your PR

Fixed dimming incomplete past tasks in event list and monthly widgets to look like in the app.

Before/After Screenshots/Screen Record

• Before:

• After:

Fixes the following issue(s)

• Fixes #203

Acknowledgement

• [x] I read the contribution guidelines.