Updated to latest npm dependencies

Author: JeremyCaney

OnTopic.Editor.AspNetCore/package-lock.json

@@ -7,15 +7,15 @@
   },
   "license": "MIT",
   "devDependencies": {
-    "bootstrap": "^4.5.2",
+    "bootstrap": "^4.5.3",
     "cssnano": "^4.1.10",
     "gulp": "^4.0.2",
     "gulp-concat": "^2.6.1",
     "gulp-if": "^3.0.0",
     "gulp-jshint": "^2.1.0",
-    "gulp-postcss": "^8.0.0",
+    "gulp-postcss": "^9.0.0",
     "gulp-sass": "^4.1.0",
-    "gulp-sourcemaps": "^2.6.5",
+    "gulp-sourcemaps": "^3.0.0",
     "gulp-uglify": "^3.0.2",
     "jquery": "^3.5.1",
     "jquery-tokeninput": "^1.6.0",