Remove outdated TODO comments for contrib 1.50.0 update

[hoteye]

PR: Remove outdated TODO comments for contrib 1.50.0 update

Description

This PR cleans up outdated TODO comments and removes duplicate configuration that is no longer needed.

Changes

• Removed TODO comments mentioning "remove after updating contrib to 1.50.0"
• Removed duplicate filesMatching configuration for GCP resource version.properties in two shadow jar tasks
• Simplified build configuration by removing unnecessary duplicate handling

Justification

The TODO comments reference updating to contrib 1.50.0, but the project is already using OpenTelemetry API 1.50.0:

• instrumentation/opentelemetry-api/opentelemetry-api-1.50/ directory exists and is actively used
• opentelemetry-api-shaded-for-instrumenting uses 1.50.0-alpha
• These TODOs are outdated and the duplicate configuration was causing unnecessary complexity

Type of change

• Cleanup / Refactoring
• Removes dead code

Testing

• Build configuration simplified without functionality change
• No test changes needed as this only removes outdated build configuration
• Gradle syntax is valid (verified)

Checklist

• My changes generate no new warnings
• I have made corresponding changes to the documentation (N/A - internal build config)
• My changes follow the style guidelines of this project
• I have performed a self-review of my own code

[laurit]

The TODO comments reference updating to contrib 1.50.0, but the project is already using OpenTelemetry API 1.50.0:

Contrib and api are different projects. Contrib version hasn't been updated yet.

[hoteye]

Thanks for the clarification!.