Revert "github actions: Switch to multiline string format suggested by GA docs"

This reverts commit 47f3cc4.

Author: bmastbergen

.github/workflows/validate-kernel-commits.yml

@@ -184,11 +184,9 @@ jobs:
           FILTERED_OUTPUT=$(echo "$OUTPUT" | grep -v "jira-user\|jira-key\|basic_auth\|Authorization\|$JIRA_API_TOKEN")
 
           echo "$FILTERED_OUTPUT"
-          {
-            echo "output<<EOF"
-            echo "$FILTERED_OUTPUT"
-            echo "EOF"
-          } >> $GITHUB_OUTPUT
+          echo "output<<'EOF'" >> $GITHUB_OUTPUT
+          echo "$FILTERED_OUTPUT" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
 
           # Check if there are any issues based on output patterns
           if echo "$FILTERED_OUTPUT" | grep -q "❌ Errors:"; then