Update error message matching (dependabot#8408)

* Update error message matching

I believe this error string never really matched the output. We could maybe find a more specific regex, but I think this is sufficient.

* lint...

npm_and_yarn/lib/dependabot/npm_and_yarn/file_updater/yarn_lockfile_updater.rb

@@ -228,9 +228,9 @@ def handle_yarn_lock_updater_error(error, yarn_lock)
           # Local path error: When installing a git dependency which
           # is using local file paths for sub-dependencies (e.g. unbuilt yarn
           # workspace project)
-          sub_dep_local_path_err = 'Package "" refers to a non-existing file'
+          sub_dep_local_path_err = "refers to a non-existing file"
           if error_message.match?(INVALID_PACKAGE) ||
-             error_message.start_with?(sub_dep_local_path_err)
+             error_message.include?(sub_dep_local_path_err)
             raise_resolvability_error(error_message, yarn_lock)
           end