Upgrade Ruby to version 3.2.3

As usual, we're updating the bundler version in our Gemfile.lock so it
uses the one included in Ruby 3.2.3, and we're also updating the
`parser` gem so it supports this version.

.gitlab-ci.yml

@@ -3,7 +3,7 @@ stages:
   - lint
 
 tests:
-  image: "ruby:3.1.4"
+  image: "ruby:3.2.3"
   stage: test
   services:
     - postgres:10.10
@@ -35,7 +35,7 @@ tests:
 # PRONTO_GITLAB_API_PRIVATE_TOKEN to your repository CI/CD settings
 # giving it the value of the Personal Access Token
 linters:
-  image: "ruby:3.1.4"
+  image: "ruby:3.2.3"
   stage: lint
   cache:
     key: consul