Bump handlebars from 4.5.1 to 4.7.6 in /samples/knockout-sp-pnp-js

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.5.1 to 4.7.6.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.5.1...v4.7.6)

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

samples/knockout-sp-pnp-js/package-lock.json

@@ -7573,22 +7573,35 @@
       }
     },
     "handlebars": {
-      "version": "4.5.1",
-      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.5.1.tgz",
-      "integrity": "sha512-C29UoFzHe9yM61lOsIlCE5/mQVGrnIOrOq7maQl76L7tYPCgC1og0Ajt6uWnX4ZTxBPnjw+CUvawphwCfJgUnA==",
+      "version": "4.7.6",
+      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.7.6.tgz",
+      "integrity": "sha512-1f2BACcBfiwAfStCKZNrUCgqNZkGsAT7UM3kkYtXuLo0KnaVfjKOyf7PRzB6++aK9STyT1Pd2ZCPe3EGOXleXA==",
       "dev": true,
       "requires": {
+        "minimist": "^1.2.5",
         "neo-async": "^2.6.0",
-        "optimist": "^0.6.1",
         "source-map": "^0.6.1",
-        "uglify-js": "^3.1.4"
+        "uglify-js": "^3.1.4",
+        "wordwrap": "^1.0.0"
       },
       "dependencies": {
+        "minimist": {
+          "version": "1.2.5",
+          "resolved": "http://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
+          "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==",
+          "dev": true
+        },
         "source-map": {
           "version": "0.6.1",
           "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
           "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
           "dev": true
+        },
+        "wordwrap": {
+          "version": "1.0.0",
+          "resolved": "https://registry.npmjs.org/wordwrap/-/wordwrap-1.0.0.tgz",
+          "integrity": "sha1-J1hIEIkUVqQXHI0CJkQa3pDLyus=",
+          "dev": true
         }
       }
     },