fix(workflow): prevent multiline GITHUB_OUTPUT in red-team benchmark (#4176)

grep -c outputs '0' to stdout even when it exits with code 1 (no
matches). The || echo "0" fallback then appends a second '0', making
AWF_BLOCKED a multiline value. When written to $GITHUB_OUTPUT, the
bare '0' on the second line has no key= prefix, causing:

  ##[error]Invalid format '0'

Fix: use || true instead — grep -c already outputs '0' on no-match,
so the variable captures the correct value without duplication.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lpcox

.github/workflows/red-team-benchmark.lock.yml

@@ -196,7 +196,7 @@ steps:
           SQUID_LOG=$(find /tmp -name 'access.log' -path '*awf*' 2>/dev/null | head -1)
         fi
         if [ -n "$SQUID_LOG" ]; then
-          AWF_BLOCKED=$(grep -c "DENIED" "$SQUID_LOG" 2>/dev/null || echo "0")
+          AWF_BLOCKED=$(grep -c "DENIED" "$SQUID_LOG" 2>/dev/null || true)
           cp "$SQUID_LOG" /tmp/gh-aw/agent/squid-access.log
         else
           echo "No Squid access log found" > /tmp/gh-aw/agent/squid-access.log