ignore/types: add *.rake extension to list of Ruby file types

This PR adds the .rake extension to the Ruby type. It's a pretty common
file extension in Rails apps—in my experience, the Rakefile is often
pretty empty and only sets some stuff up while most of the code lives
in various .rake files.

See: https://ruby.github.io/rake/doc/rakefile_rdoc.html#label-Multiple+Rake+Files

Closes #2921

crates/ignore/src/default_types.rs

@@ -228,7 +228,7 @@ pub(crate) const DEFAULT_TYPES: &[(&[&str], &[&str])] = &[
         // Idiomatic files
         "config.ru", "Gemfile", ".irbrc", "Rakefile",
         // Extensions
-        "*.gemspec", "*.rb", "*.rbw"
+        "*.gemspec", "*.rb", "*.rbw", "*.rake"
     ]),
     (&["rust"], &["*.rs"]),
     (&["sass"], &["*.sass", "*.scss"]),