python-wheels workflows: add sync self-check job

Add sync-self-check job that fails if emu/pub workflows diverge beyond
the expected differences (name, cisco-actions/* mirrors).

Author: andrewchi

.github/workflows/emu-python-wheels.yml

@@ -1,9 +1,9 @@
-# ┌─────────────────────────────────────────────────────────────────┐
-# │ IMPORTANT: This file MUST stay in sync with                     │
-# │ pub-python-wheels.yml. The only expected differences are the    │
-# │ workflow name and the cisco-actions/* mirror references.        │
-# │ Do NOT accept PRs where these files diverge in any other way.   │
-# └─────────────────────────────────────────────────────────────────┘
+###################################################################
+# IMPORTANT: This file MUST stay in sync with
+# pub-python-wheels.yml. The only expected differences are the
+# workflow name and the cisco-actions/* mirror references.
+# Do NOT accept PRs where these files diverge in any other way.
+###################################################################
 name: "[EMU] Python Wheels"
 
 on:
@@ -13,7 +13,24 @@ on:
       - main
 
 jobs:
+  sync-self-check:
+    name: Sync self-check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Check diff between emu and pub workflow files
+        run: |
+          MAX_DIFF_LINES=4
+          COUNT=$(diff -y --suppress-common-lines .github/workflows/emu-python-wheels.yml .github/workflows/pub-python-wheels.yml | wc -l)
+          echo "Differing lines: $COUNT (max allowed: $MAX_DIFF_LINES)"
+          if [ "$COUNT" -gt "$MAX_DIFF_LINES" ]; then
+            echo "::error::emu-python-wheels.yml and pub-python-wheels.yml have diverged ($COUNT differing lines, max $MAX_DIFF_LINES)"
+            diff .github/workflows/emu-python-wheels.yml .github/workflows/pub-python-wheels.yml || true
+            exit 1
+          fi
+
   build-mercury-wheels:
+    needs: sync-self-check
     name: Build wheels on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     environment:

.github/workflows/pub-python-wheels.yml

@@ -1,9 +1,9 @@
-# ┌─────────────────────────────────────────────────────────────────┐
-# │ IMPORTANT: This file MUST stay in sync with                     │
-# │ emu-python-wheels.yml. The only expected differences are the    │
-# │ workflow name and the cisco-actions/* mirror references.        │
-# │ Do NOT accept PRs where these files diverge in any other way.   │
-# └─────────────────────────────────────────────────────────────────┘
+###################################################################
+# IMPORTANT: This file MUST stay in sync with
+# emu-python-wheels.yml. The only expected differences are the
+# workflow name and the cisco-actions/* mirror references.
+# Do NOT accept PRs where these files diverge in any other way.
+###################################################################
 name: "[PUB] Python Wheels"
 
 on:
@@ -13,7 +13,24 @@ on:
       - main
 
 jobs:
+  sync-self-check:
+    name: Sync self-check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Check diff between emu and pub workflow files
+        run: |
+          MAX_DIFF_LINES=4
+          COUNT=$(diff -y --suppress-common-lines .github/workflows/emu-python-wheels.yml .github/workflows/pub-python-wheels.yml | wc -l)
+          echo "Differing lines: $COUNT (max allowed: $MAX_DIFF_LINES)"
+          if [ "$COUNT" -gt "$MAX_DIFF_LINES" ]; then
+            echo "::error::emu-python-wheels.yml and pub-python-wheels.yml have diverged ($COUNT differing lines, max $MAX_DIFF_LINES)"
+            diff .github/workflows/emu-python-wheels.yml .github/workflows/pub-python-wheels.yml || true
+            exit 1
+          fi
+
   build-mercury-wheels:
+    needs: sync-self-check
     name: Build wheels on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     environment: