fix: notebook panel unsaved indicator not showing after dragging a panel

[dsmmcken]

Steps to reproduce the issue:

1. Have an unsaved notebook with the blue dot indicating unsaved work
2. Drag the panel to a new location

Expected:
Notebook still has unsaved indicator

Actual:
Notebook doesn't have indicator until something causes it to re-render.

[codecov]

Codecov Report

Merging #1325 (74f6ee7) into main (6ae174c) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #1325      +/-   ##
==========================================
- Coverage   45.95%   45.94%   -0.01%     
==========================================
  Files         493      493              
  Lines       34404    34410       +6     
  Branches     8580     8581       +1     
==========================================
  Hits        15811    15811              
- Misses      18542    18548       +6     
  Partials       51       51              

Flag	Coverage Δ
unit	45.94% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ashboard-core-plugins/src/panels/NotebookPanel.tsx	1.57% <0.00%> (-0.02%)	⬇️