Upgrade Ruby to version 3.1.4

Note we updated the `mail` gem in commit 103742847, which is necesary
for Ruby 3.1 because it adds the net-smtp dependency. The net-smtp
library was removed from Ruby in Ruby 3.1, and if we don't include it,
we get an error:

```
cannot load such file -- net/smtp (LoadError)
```

We're also updating the Bundler version in the Gemfile.lock so it's the
one included in Ruby 3.1. Without updating it, we get a warning:

```
Calling `DidYouMean::SPELL_CHECKERS.merge!(error_name => spell_checker)'
has been deprecated. Please call `DidYouMean.correct_error(error_nam e,
spell_checker)' instead.
```

Finally, in order to make Capistrano work, we need to add a couple more
changes:

* Make the net-ssh gem compatible with SSL 3.0; done in commit b2eec088b
* Explicitly allow aliases in the `deploy-secrets.yml` file because
  Psych 4.x (included in Ruby 3.1) doesn't load aliases without this
  option

.gitlab-ci.yml

@@ -3,7 +3,7 @@ stages:
   - lint
 
 tests:
-  image: "ruby:3.0.6"
+  image: "ruby:3.1.4"
   stage: test
   services:
     - postgres:10.10
@@ -34,7 +34,7 @@ tests:
 # PRONTO_GITLAB_API_PRIVATE_TOKEN to your repository CI/CD settings
 # giving it the value of the Personal Access Token
 linters:
-  image: "ruby:3.0.6"
+  image: "ruby:3.1.4"
   stage: lint
   cache:
     key: consul

.ruby-version

@@ -1 +1 @@
-3.0.6
+3.1.4

Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3.0.6-buster
+FROM ruby:3.1.4-buster
 
 ENV DEBIAN_FRONTEND noninteractive
 

Gemfile.lock

@@ -784,4 +784,4 @@ DEPENDENCIES
   wkhtmltopdf-binary (~> 0.12.6)
 
 BUNDLED WITH
-   2.2.33
+   2.3.26

README.md

@@ -38,7 +38,7 @@ You can access the main website of the project at [http://consuldemocracy.org](h
 
 **NOTE**: For more detailed instructions check the [docs](https://docs.consuldemocracy.org)
 
-Prerequisites: install git, Ruby 3.0.6, CMake, pkg-config, shared-mime-info, Node.js and PostgreSQL (>=9.5).
+Prerequisites: install git, Ruby 3.1.4, CMake, pkg-config, shared-mime-info, Node.js and PostgreSQL (>=9.5).
 
 ```bash
 git clone https://github.com/consuldemocracy/consuldemocracy.git

README_ES.md

@@ -36,7 +36,7 @@ Puedes acceder a la página principal del proyecto en [http://consuldemocracy.or
 
 **NOTA**: para unas instrucciones más detalladas consulta la [documentación](https://docs.consuldemocracy.org)
 
-Prerequisitos: tener instalado git, Ruby 3.0.6, CMake, pkg-config, shared-mime-info, Node.js y PostgreSQL (9.5 o superior).
+Prerequisitos: tener instalado git, Ruby 3.1.4, CMake, pkg-config, shared-mime-info, Node.js y PostgreSQL (9.5 o superior).
 
 ```bash
 git clone https://github.com/consuldemocracy/consuldemocracy.git

config/deploy.rb

@@ -2,7 +2,7 @@
 lock "~> 3.17.1"
 
 def deploysecret(key, default: "")
-  @deploy_secrets_yml ||= YAML.load_file("config/deploy-secrets.yml")[fetch(:stage).to_s]
+  @deploy_secrets_yml ||= YAML.load_file("config/deploy-secrets.yml", aliases: true)[fetch(:stage).to_s]
   @deploy_secrets_yml.fetch(key.to_s, default)
 end