[COMPLIANCE] Add Copyright and License Headers (Batch 1 of 1) (#589)

Co-authored-by: hashicorp-copywrite[bot] <110428419+hashicorp-copywrite[bot]@users.noreply.github.com>

src/secrets.js

@@ -1,3 +1,8 @@
+/**
+ * Copyright IBM Corp. 2019, 2025
+ * SPDX-License-Identifier: MIT
+ */
+
 const jsonata = require("jsonata");
 const { WILDCARD, WILDCARD_UPPERCASE} = require("./constants");
 const { normalizeOutputKey } = require("./utils");