Update open source timeline events and fix notification dependency

[jagrati7305]

Problem / Issue No.

• The open source timeline screen contained outdated 2024 event schedules and application periods in opso_timeline.dart.
• Fixes Update Open Source Timeline Events and Dates for Current Year #423

Describe Problem / Root Cause

• Several open-source program events such as Google Summer of Code, Outreachy, Hacktoberfest, MLH Fellowship, and others were still using outdated 2024 timeline data.

Solution proposed

• Updated the timeline data in opso_timeline.dart with the latest available schedules and application periods for open-source programs.
• Verified updated timelines using official program sources.
• Moved awesome_notifications from dev_dependencies to dependencies in pubspec.yaml to properly support runtime notification services.
• Verified that notification scheduling and display continue to work correctly with updated event dates.

Additional Information

• Tested the application locally using flutter run.
• Verified updated timeline UI and notification scheduling behavior.

Screenshots

• Updated Screenshot (Fixes/Solution)

[netlify]

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[github-actions]

Thank you for submitting your pull request! We'll review it as soon as possible.

[andoriyaprashant]

@jagrati7305 Please Resolve Merge Conflicts
Thanks

[jagrati7305]

@andoriyaprashant Resolved merge conflicts. Please review again.

[andoriyaprashant]

Thanks @jagrati7305

[jagrati7305]

@andoriyaprashant Hi, my PR has been merged successfully. Could the appropriate labels also be added for tracking purposes? Thanks!

[andoriyaprashant]

@andoriyaprashant Hi, my PR has been merged successfully. Could the appropriate labels also be added for tracking purposes? Thanks!

Done @jagrati7305