fix: pin ruby action to specific version (aws#8491)

Pin Ruby action to specific version until Lambda Buidlers support
`bundler` 4.0.0

Author: valerena

.github/workflows/build.yml

@@ -160,7 +160,8 @@ jobs:
       - uses: actions/setup-go@v6
         with:
           go-version: '1.19'
-      - uses: ruby/setup-ruby@v1
+      # Pin to specific version until Lambda Builders support bundler 4.0.0
+      - uses: ruby/setup-ruby@v1.268.0
         with:
           ruby-version: "3.3"
       - uses: actions/setup-node@v6