tweak weight of rubric comments
tweak weight of rubric comments

The scoring comments wee being given a light weight instead of a normal
making them less accessible to read

closes EVAL-2431
flag=none

Test Plan:
    -check screen shots before/after

Change-Id: I5611e2d6a8ec9f5396d08534c7c3bd6a60b6e9a9
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/300413
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Aaron Shafovaloff <d0ee6b99167c663aba7bc3efd806fe8d6cad437b@instructure.com>
QA-Review: Kai Bjorkman <4693b3d9e71784d629732770ab5e83ed8fbdb83e@instructure.com>
Product-Review: Deborah Kwak <5498c4751d2b9365fe654627c4991c217ce972a8@instructure.com>

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