fix: amendment version data source changed

[pdp2121]

High Level Overview of Change

The repo xrpl-dev-portal was updated recently. The data source link for fetching amendment version needs to be updated accordingly to ensure data shows up.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (non-breaking change that only restructures code)
• Tests (You added tests for code that already exists, or your new feature included in this PR)
• Documentation Updates
• Translation Updates
• Release

Test Plan

Pass tests.