Fix rake ci:pin_build_manifest

Author: kateinoigakukun

CONTRIBUTING.md

@@ -138,7 +138,7 @@ $ npm install --save @ruby/wasm-wasi@2.7.2-2025-10-03-a
 When a new version of Ruby is released, the following steps need to be taken to add support for it in ruby.wasm:
 
 1. Update `lib/ruby_wasm/cli.rb`:
-   - Add a new entry in the `build_source_aliases` method for the new version
+   - Add a new entry in the `build_config_aliases` method for the new version
    - Specify the tarball URL and required default extensions
 
 2. Update `Rakefile`:

rakelib/ci.rake

@@ -1,7 +1,8 @@
 def latest_build_sources
   BUILD_SOURCES
     .filter_map do |name|
-      src = RubyWasm::CLI.build_source_aliases(LIB_ROOT)[name]
+      config = RubyWasm::CLI.build_config_aliases(LIB_ROOT)[name]
+      src = config[:src]
       case src[:type]
       when "github"
         url = "repos/#{src[:repo]}/commits/#{src[:rev]}"
@@ -23,7 +24,8 @@ def release_note
 EOS
 
   BUILD_SOURCES.each do |name|
-    source = RubyWasm::CLI.build_source_aliases(LIB_ROOT)[name]
+    config = RubyWasm::CLI.build_config_aliases(LIB_ROOT)[name]
+    source = config[:src]
     case source[:type]
     when "github"
       output +=