Bump handlebars from 4.4.5 to 4.5.1

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.4.5 to 4.5.1.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/v4.5.1/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.4.5...v4.5.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -37,7 +37,7 @@
         "@actions-rs/core": "0.0.7",
         "@actions/core": "^1.1.1",
         "@actions/github": "^1.1.0",
-        "handlebars": "^4.4.5"
+        "handlebars": "^4.5.1"
     },
     "devDependencies": {
         "@typescript-eslint/eslint-plugin": "^2.5.0",