Update polyfill for datetime-local

Bloody Firefox. We love to hate you. Proper CSS of the fill to come, SoonTM.

Closes #391

package.json

@@ -5,7 +5,6 @@
   "author": "Tom Price",
   "license": "MIT",
   "dependencies": {
-    "@activix/bootstrap-datetimepicker": "^2.0.7",
     "@forevolve/bootstrap-dark": "^1.0.0-alpha.1075",
     "@fortawesome/fontawesome-free": "^5.13.1",
     "ajax-bootstrap-select": "^1.4.5",
@@ -14,6 +13,7 @@
     "bootstrap": "^4.5.2",
     "bootstrap-select": "^1.13.17",
     "dark-mode-switch": "^1.0.0",
+    "flatpickr": "^4.6.6",
     "fullcalendar": "^3.10.2",
     "gulp-if": "^3.0.0",
     "gulp-rename": "^2.0.0",