perf: Optimize workflow step order for efficiency

Reorder steps to check what's needed first, then only set up Docker environment if build is actually required. This avoids expensive Docker setup when only label changes occur.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/showtime-trigger.yml

@@ -89,26 +89,7 @@ jobs:
           echo "deploy_needed=$DEPLOY" >> $GITHUB_OUTPUT
           echo "pr_number=$PR_NUM" >> $GITHUB_OUTPUT
 
-      - name: Checkout repository for local actions
-        if: steps.check.outputs.build_needed == 'true'
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 1
-          persist-credentials: false
-
-      - name: Setup Docker Environment
-        if: steps.check.outputs.build_needed == 'true'
-        uses: ./.github/actions/setup-docker
-        with:
-          dockerhub-user: ${{ env.DOCKERHUB_USER }}
-          dockerhub-token: ${{ env.DOCKERHUB_TOKEN }}
-          build: "true"
-
-      - name: Setup supersetbot
-        if: steps.check.outputs.build_needed == 'true'
-        uses: ./.github/actions/setup-supersetbot/
-
-      - name: Get PR SHA for build
+      - name: Get SHA for potential build
         id: sha
         if: steps.check.outputs.build_needed == 'true'
         run: |
@@ -140,8 +121,21 @@ jobs:
         uses: actions/checkout@v4
         with:
           ref: ${{ steps.sha.outputs.build_sha }}
+          fetch-depth: 1
           persist-credentials: false
 
+      - name: Setup Docker Environment
+        if: steps.check.outputs.build_needed == 'true'
+        uses: ./.github/actions/setup-docker
+        with:
+          dockerhub-user: ${{ env.DOCKERHUB_USER }}
+          dockerhub-token: ${{ env.DOCKERHUB_TOKEN }}
+          build: "true"
+
+      - name: Setup supersetbot
+        if: steps.check.outputs.build_needed == 'true'
+        uses: ./.github/actions/setup-supersetbot/
+
       - name: Build Docker image
         if: steps.check.outputs.build_needed == 'true'
         run: |