Explicitly add terser to node_modules/

While we were already including terser as a transitive dependency
via rollup-plugin-terser, the resolved version was quite old.
By explicitly adding terser to our node_modules deps, we can ensure
we are using a recent version.

R=aerotwist@chromium.org

Bug: none
Change-Id: Ie10a808ce3cbe80138183a9704816aa966a01f16
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2975283
Reviewed-by: Paul Lewis <aerotwist@chromium.org>
Commit-Queue: Paul Lewis <aerotwist@chromium.org>
Auto-Submit: Tim van der Lippe <tvanderlippe@chromium.org>

node_modules/terser/package.json

@@ -4,7 +4,7 @@
   "homepage": "https://terser.org",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "5.3.8",
+  "version": "5.6.1",
   "engines": {
     "node": ">=10"
   },
@@ -48,16 +48,16 @@
   },
   "devDependencies": {
     "@ls-lint/ls-lint": "^1.9.2",
-    "acorn": "^7.4.0",
-    "astring": "^1.4.1",
-    "eslint": "^7.0.0",
+    "acorn": "^8.0.5",
+    "astring": "^1.6.2",
+    "eslint": "^7.19.0",
     "eslump": "^2.0.0",
     "esm": "^3.2.25",
-    "mocha": "^8.0.0",
+    "mocha": "^8.2.1",
     "pre-commit": "^1.2.2",
-    "rimraf": "^3.0.0",
-    "rollup": "2.0.6",
-    "semver": "^7.1.3"
+    "rimraf": "^3.0.2",
+    "rollup": "2.38.4",
+    "semver": "^7.3.4"
   },
   "scripts": {
     "test": "node test/compress.js && mocha test/mocha",