Fix CI: replace require_relative with require in -e context

require_relative cannot infer basepath when used in ruby -e, causing
LoadError. Using require instead works with the -Itest load path.

https://claude.ai/code/session_01CvCNpdSjh1STBdmS9n5DN9

Author: claude

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
           ruby-version: ${{ matrix.ruby-version }}
 
       - name: Run tests
-        run: ruby -Ilib -Itest -e "Dir['test/test_*.rb'].each { |f| require_relative f }"
+        run: ruby -Ilib -Itest -e "Dir['test/test_*.rb'].each { |f| require f }"
 
       - name: Verify gem builds
         run: gem build ipdata.gemspec

.github/workflows/release.yml

@@ -75,7 +75,7 @@ jobs:
           ruby-version: "3.3"
 
       - name: Run tests
-        run: ruby -Ilib -Itest -e "Dir['test/test_*.rb'].each { |f| require_relative f }"
+        run: ruby -Ilib -Itest -e "Dir['test/test_*.rb'].each { |f| require f }"
 
       - name: Build gem
         run: gem build ipdata.gemspec