Bump ruby/setup-ruby from 1.255.0 to 1.256.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.255.0 to 1.256.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@829114f...efbf473)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.256.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/cibuild.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v5
-      - uses: ruby/setup-ruby@829114fc20da43a41d27359103ec7a63020954d4 # v1.255.0
+      - uses: ruby/setup-ruby@efbf473cab83af4468e8606cc33eca9281bb213f # v1.256.0
         with:
           ruby-version: ${{ matrix.ruby }}
       - name: script/cibuild

.github/workflows/pages-gem.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v5
       - name: Setup Ruby
-        uses: ruby/setup-ruby@829114fc20da43a41d27359103ec7a63020954d4 # v1.255.0
+        uses: ruby/setup-ruby@efbf473cab83af4468e8606cc33eca9281bb213f # v1.256.0
         with:
           ruby-version: "3.3"
       - name: Build gem