[CI][sycl-rel] Update scheduled launch

.github/workflows/sycl-rel-nightly-launch.yml

@@ -1,4 +1,4 @@
-# Gihub Actions launch scheduled workflows of the main branch only (sycl).
+# Github Actions launch scheduled workflows of the main branch only (sycl).
 # This is a workaround to set a scheduled launch of the sycl-rel-nightly.yml
 # workflow, which is located on the sycl-rel-* branch.
 
@@ -7,10 +7,8 @@ name: Scheduled sycl-rel-nightly launch
 permissions: read-all
 
 on:
-  # The sycl-rel-nightly.yml workflow file on the sycl-rel-6_2 branch is most
-  # likely stale. Do not schedule before it's updated.
-  # schedule:
-    # - cron: '0 3 * * *'
+  schedule:
+    - cron: '0 3 * * *'
   workflow_dispatch:
 
 jobs:
@@ -23,5 +21,19 @@ jobs:
       - name: Launch
         env:
           GH_TOKEN: ${{ github.token }}
+        # To avoid excessive scheduled runs this script also checks if there are
+        # new commits since the last run - it checks if the latest commit is
+        # older >24h. That means the previous run already tested this commit.
         run: |
-          gh workflow run sycl-rel-nightly.yml --repo ${{ github.repository }} --ref sycl-rel-6_2
+          if [ "$GITHUB_EVENT_NAME" = "schedule" ]; then
+            latest_commit_time=$(curl -s https://api.github.com/repos/intel/llvm/commits/sycl-rel-6_2 | jq -r '.commit.committer.date')
+            echo $latest_commit_time
+            latest_commit_epoch=$(date -d "$latest_commit_time" +%s)
+            now_epoch=$(date +%s)
+            diff=$((now_epoch - latest_commit_epoch))
+            if [ "$diff" -lt 86400 ]; then
+              gh workflow run sycl-rel-nightly.yml --repo "${GITHUB_REPOSITORY}" --ref sycl-rel-6_2
+            fi
+          else
+            gh workflow run sycl-rel-nightly.yml --repo "${GITHUB_REPOSITORY}" --ref sycl-rel-6_2
+          fi