fix: don't accidentally bundle paragon CSS x2

src/editors/containers/VideoEditor/components/VideoSettingsModal/components/DurationWidget/index.scss

@@ -1,4 +1,7 @@
-@import "@openedx/paragon/scss/core/core";
+// do NOT @import "@openedx/paragon/scss/core/core"; in any files in this repo, or it will add 400 kB of extra CSS
+// to the MFE each time you do so. The following are OK because they are only defining variables like $grey-500:
+@import "@edx/brand/paragon/variables";
+@import "@openedx/paragon/scss/core/_variables";
 
 .total-label {
     border: 1px solid $gray-500;

src/editors/containers/VideoUploadEditor/index.scss

@@ -1,4 +1,7 @@
-@import "@openedx/paragon/scss/core/core";
+// do NOT @import "@openedx/paragon/scss/core/core"; in any files in this repo, or it will add 400 kB of extra CSS
+// to the MFE each time you do so. The following are OK because they are only defining variables like $grey-500:
+@import "@edx/brand/paragon/variables";
+@import "@openedx/paragon/scss/core/_variables";
 
 .dropzone-middle {
   border: 2px dashed #ccc;