Refactor CI workflows and add Dependabot configuration (#67)

* fix: remove duplicate pnpm setup step in CI and build workflows

* fix: remove version specification for pnpm setup in CI and build workflows

* feat: add Dependabot configuration for GitHub Actions updates

* chore: auto-fix linting and formatting issues

.github/dependabot.yml

@@ -0,0 +1,17 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # GitHub Actions
+    directory: "/"
+    schedule:
+      interval: "daily"
+    allow:
+      - dependency-type: "all"
+    groups:
+      all:
+        patterns:
+          - "*"