fix: Gemfile & Gemfile.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-7164639

Gemfile

@@ -4,7 +4,7 @@ source 'http://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '~> 6.1'
+gem 'rails', '~> 7.0', '>= 7.0.0'
 # Use sqlite3 as the database for Active Record
 # gem 'sqlite3', '~> 1.3'
 # Use postgres as the database for Active Record
@@ -32,7 +32,7 @@ gem 'jquery-rails', '>= 4.6.0'
 # Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
 gem 'turbolinks', '~> 5'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem 'jbuilder', '~> 2.11', '>= 2.11.5'
+gem 'jbuilder', '~> 2.12', '>= 2.12.0'
 # Use Redis adapter to run Action Cable in production
 gem 'redis', '~> 4.2'
 # Use ActiveModel has_secure_password
@@ -41,11 +41,11 @@ gem 'redis', '~> 4.2'
 gem 'jwt', '~> 2.2.2'
 gem 'oauth', '~> 0.5.1'
 
-gem 'doorkeeper', '~> 5.6.9'
+gem 'doorkeeper', '~> 5.7.0'
 gem 'repost', '~> 0.3.8'
 
 gem 'lodash-rails'
-gem 'react-rails', '>= 3.2.0'
+gem 'react-rails', '>= 3.2.1'
 
 gem 'rails_lti2_provider', git: 'https://github.com/blindsidenetworks/rails_lti2_provider.git', tag: '0.1.9'
 
@@ -56,7 +56,7 @@ gem 'simple_oauth', git: 'https://github.com/blindsidenetworks/simple_oauth.git'
 gem 'activerecord-session_store', '>= 2.1.0'
 
 # frontend
-gem 'bootstrap', '~> 4.6.0'
+gem 'bootstrap', '~> 5.0.0'
 gem 'font-awesome-sass', '~> 6.4.0'
 gem 'popper_js', '>= 1.16'