feat: remove offset when studio header exists

[khudym]

Description

• this PR proposes making the TinyMce toolbar_sticky_offset to 0 when there is "studio-header" on the page

Before

Schedule & details page

Course updates page

After

Schedule & details page

Course updates page

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.92%. Comparing base (c84e322) to head (ccbe859). Report is 4 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #491 +/- ## ========================================== + Coverage 88.86% 88.92% +0.05% ========================================== Files 248 248 Lines 4534 4540 +6 Branches 933 940 +7 ========================================== + Hits 4029 4037 +8 + Misses 474 470 -4 - Partials 31 33 +2 ```

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