ci: redistribute canonical secret-scanner.yml (concurrency-cancel guard) (Refs hyperpolymath/standards#122)

Author: hyperpolymath

.github/workflows/secret-scanner.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: PMPL-1.0
 # Prevention workflow - scans for hardcoded secrets before they reach main
 name: Secret Scanner
 
@@ -7,6 +7,14 @@ on:
   push:
     branches: [main]
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -19,7 +27,7 @@ jobs:
           fetch-depth: 0  # Full history for scanning
 
       - name: TruffleHog Secret Scan
-        uses: trufflesecurity/trufflehog@8a8ef8526528d8a4ff3e2c90be08e25ef8efbd9b # v3
+        uses: trufflesecurity/trufflehog@6c05c4a00b91aa542267d8e32a8254774799d68d # v3
         with:
           # The v3 action injects --fail automatically on pull_request events.
           # Passing --fail here triggers "flag 'fail' cannot be repeated".
@@ -70,4 +78,4 @@ jobs:
           if [ $found -eq 1 ]; then
             echo "::error::Potential hardcoded secrets detected. Use environment variables instead."
             exit 1
-          fi
+          fi