[Security] Bump acorn from 5.7.3 to 6.4.1 (#2137)

Bumps [acorn](https://github.com/acornjs/acorn) from 5.7.3 to 6.4.1. **This update includes a security fix.**
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/5.7.3...6.4.1)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

package-lock.json

@@ -8240,25 +8240,10 @@
             "negotiator": "0.6.2"
           }
         },
-        "acorn": {
-          "version": "6.3.0",
-          "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.3.0.tgz",
-          "integrity": "sha512-/czfa8BwS88b9gWQVhc8eknunSA2DoJpJyTQkhheIf5E48u1N0R4q/YxxsAeqRrmK9TQ/uYfgLDfZo91UlANIA=="
-        },
         "acorn-dynamic-import": {
           "version": "3.0.0",
           "resolved": "https://registry.npmjs.org/acorn-dynamic-import/-/acorn-dynamic-import-3.0.0.tgz",
-          "integrity": "sha512-zVWV8Z8lislJoOKKqdNMOB+s6+XV5WERty8MnKBeFgwA+19XJjJHs2RP5dzM57FftIs+jQnRToLiWazKr6sSWg==",
-          "requires": {
-            "acorn": "^5.0.0"
-          },
-          "dependencies": {
-            "acorn": {
-              "version": "5.7.3",
-              "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
-              "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw=="
-            }
-          }
+          "integrity": "sha512-zVWV8Z8lislJoOKKqdNMOB+s6+XV5WERty8MnKBeFgwA+19XJjJHs2RP5dzM57FftIs+jQnRToLiWazKr6sSWg=="
         },
         "acorn-jsx": {
           "version": "5.1.0",
@@ -20493,11 +20478,6 @@
             "webpack-sources": "^1.4.1"
           },
           "dependencies": {
-            "acorn": {
-              "version": "5.7.3",
-              "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
-              "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw=="
-            },
             "schema-utils": {
               "version": "1.0.0",
               "resolved": "https://registry.npmjs.org/schema-utils/-/schema-utils-1.0.0.tgz",