Fix Release CI workflow failure

[yhk1038]

Problem

The v0.0.44 Release workflow failed due to two issues:

1. WASM build failure

• wasm/build.sh tries to copy lib/t_ruby/rbs_generator.rb but the file doesn't exist
• Error: cp: cannot stat 'lib/t_ruby/rbs_generator.rb': No such file or directory

2. RubyGems authentication failure

• RUBYGEMS_API_KEY secret was not configured (401 error)

Solution

1. Remove rbs_generator.rb from CORE_FILES in wasm/build.sh
2. Configure RUBYGEMS_API_KEY in GitHub Secrets

Related

• Failed run: https://github.com/type-ruby/t-ruby/actions/runs/21093754526