Add missing ReadFiles action for WebSocket Duo Agent Platform clients

Summary

As pointed out by @halilcoban:

Hi @erran I think I found the issue. This is happening because grpc definitions for Rails were not updated. The  read_files action is not there.

Based on docs, I'll update the gem in the GitLab repository.This impacts customers who are using websockets to connect to DWS.

Unfortunately this means we will also need a backport the ruby gem update for GitLab 18.3 and earlier.

Steps to reproduce

Attempt to use the read files action over a WebSocket connection when targeting a GitLab 18.2 or 18.3 instance which does not have the appropriate protobuf/gRPC action available to it for the Ruby client to leverage.

Example Project

What is the current bug behavior?

The action fails which was triggering upstream errors in the Duo Workflow Service and Node Executor when using WebSocket connections.

What is the expected correct behavior?

The gRPC client version GitLab monolith should be respected or we should backport the tool to versions where it did not yet exist.

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

   (For installations with omnibus-gitlab package run and paste the output of: \\\\\\\`sudo gitlab-rake gitlab:env:info\\\\\\\`)  (For installations from source run and paste the output of: \\\\\\\`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production\\\\\\\`)    

Results of GitLab application Check

Expand for output related to the GitLab application check

  (For installations with omnibus-gitlab package run and paste the output of: \\\`sudo gitlab-rake gitlab:check SANITIZE=true\\\`)  (For installations from source run and paste the output of: \\\`sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true\\\`)  (we will only investigate if the tests are passing)   

Possible fixes

Patch release information for backports

If the bug fix needs to be backported in a patch release to a version under the maintenance policy, please follow the steps on the patch release runbook for GitLab engineers.

Refer to the internal "Release Information" dashboard for information about the next patch release, including the targeted versions, expected release date, and current status.

High-severity bug remediation

To remediate high-severity issues requiring an internal release for single-tenant SaaS instances, refer to the internal release process for engineers.