Migrate to ESM and upgrade dependencies (#1574)

* Migrate to ESM

* updated package.json version

* Update README for v6 and clean up dev dependencies

* Remove unused ts-node

* fix audit issue

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Co-authored-by: gowridurgad <gowridurgad@gmail.com>

.licensed.yml

@@ -10,7 +10,11 @@ allowed:
   - mit
   - cc0-1.0
   - unlicense
+  - blueoak-1.0.0
 
 reviewed:
   npm:
-     - "@actions/http-client"
+     - "@actions/http-client"
+     - balanced-match
+     - brace-expansion
+     - fast-content-type-parse