chore(deps): update dependency ruby to v4

Author: renovate[bot]

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1"
+          ruby-version: "4.0.1"
           bundler-cache: true
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -58,7 +58,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1"
+          ruby-version: "4.0.1"
           bundler-cache: true
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
@@ -80,7 +80,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1"
+          ruby-version: "4.0.1"
           bundler-cache: true
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3