Add Ruby 4.0 to the test matrix

The required_ruby_version of both gemspecs is `>= 3.1`, so anything
released past that should pass the suite. Add 4.0 to the matrix to
catch incompatibilities ahead of the next major Ruby cycle, alongside
3.2 and 3.3 already covered.

Author: skelz0r

.github/workflows/clients-ruby.yml

@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.2', '3.3']
+        ruby: ['3.2', '3.3', '4.0']
     steps:
       - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
@@ -41,7 +41,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.2', '3.3']
+        ruby: ['3.2', '3.3', '4.0']
     steps:
       - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
@@ -61,7 +61,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.2', '3.3']
+        ruby: ['3.2', '3.3', '4.0']
     steps:
       - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1

clients/ruby/README.md

@@ -121,7 +121,7 @@ bin/scaffold_resources --api all --check   # idem pour les resources
 ```
 
 La CI ([`.github/workflows/clients-ruby-tests.yml`](../../.github/workflows/clients-ruby-tests.yml))
-exécute les 3 suites rspec sur Ruby 3.2 + 3.3 et ces deux `--check`.
+exécute les 3 suites rspec sur Ruby 3.2 + 3.3 + 4.0 et ces deux `--check`.
 
 ## Quickstart consommateur