Revert "Ruby: extract rbi files"

This reverts commit ba9342e0f38f4468d04bad987a8f69e95fdbdd5f.

ruby/autobuilder/src/main.rs

@@ -16,7 +16,6 @@ fn main() -> std::io::Result<()> {
     cmd.arg("database")
         .arg("index-files")
         .arg("--include-extension=.rb")
-        .arg("--include-extension=.rbi")
         .arg("--include-extension=.erb")
         .arg("--include-extension=.gemspec")
         .arg("--include=**/Gemfile")

ruby/codeql-extractor.yml

@@ -8,7 +8,6 @@ file_types:
     display_name: Ruby files
     extensions:
        - .rb
-       - .rbi
   - name: erb
     display_name: Ruby templates
     extensions: