Add deprecated workflow

.github/workflows/check-deprecated-exercises.yml

@@ -0,0 +1,15 @@
+name: Deprecated
+
+on:
+  pull_request:
+
+jobs:
+  test-deprecated:
+    name: Check for deprecated exercises
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        with:
+          fetch-depth: 0
+      - name: Test deprecated exercises using test-deprecated-exercises
+        run: bin/test-deprecated-exercises

bin/test-deprecated-exercises

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# Determine the base branch of the PR
+BASE_BRANCH=${GITHUB_BASE_REF:-main}
+
+# Fetch full history for proper diff
+git fetch origin "$BASE_BRANCH"
+
+# Compute merge base
+MERGE_BASE=$(git merge-base HEAD origin/"$BASE_BRANCH")
+
+# Get changed files relative to merge base
+changed_files=$(git diff --name-only "$MERGE_BASE" HEAD)
+
+# Extract unique exercise directories
+changed_exercises=$(echo "$changed_files" | grep -E '^exercises/(practice|concept)/' || true)
+changed_exercises=$(echo "$changed_exercises" | cut -d/ -f1-3 | sort -u)
+
+# Early exit if no exercise changed
+if [ -z "$changed_exercises" ]; then
+  echo "No exercises changed!"
+  exit 0
+fi
+
+# Load deprecated exercises from config.json
+deprecated_exercises=$(jq -r '
+  [ 
+    (.exercises.concept[]? | select(.status=="deprecated") | "exercises/concept/" + .slug),
+    (.exercises.practice[]? | select(.status=="deprecated") | "exercises/practice/" + .slug)
+  ] | .[]
+' config.json)
+
+# Check for deprecated ones
+for ex in $changed_exercises; do
+  if echo "$deprecated_exercises" | grep -qx "$ex"; then
+    echo "❌ Deprecated exercise changed: $ex"
+    exit 1
+  fi
+done
+
+echo "✅ No deprecated exercises changed!"