Add conditional check for release tag in Buildkite pipeline (#4335)

* ci(buildkite): add conditional check for release tag in pipeline.yml

.buildkite/pipeline.yaml

@@ -11,8 +11,17 @@ x-defaults: &defaults
         run: build
 
 steps:
+  - name: ":sleuth_or_spy: Checking for release tag"
+    key: "is_released"
+    branches: "main"
+    # we assume that all releases with have a tag and that tag with have a @ version format
+    if: build.tag =~ /@(\d+\.\d+\.\d+)/ && build.tag =~ /^(?:(?!canary).)*$/
+
+  - wait
+
   - name: ":package: Build (storybook)"
     branches: "main"
+    depends_on: "is_released"
     command: ".buildkite/scripts/build-storybook.sh"
     timeout_in_minutes: 15
     artifact_paths: "./storybook.tar.gz"