fix changelog link

Author: clutchski

braintrust.gemspec

@@ -16,7 +16,7 @@ Gem::Specification.new do |spec|
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
-  spec.metadata["changelog_uri"] = "#{spec.homepage}/blob/main/CHANGELOG.md"
+  spec.metadata["changelog_uri"] = "#{spec.homepage}/releases"
 
   # Specify which files should be added to the gem when it is released.
   spec.files = Dir.glob(%w[