Notebook: delete notebook cell doesn't clear output

[rebornix]

Issue Type: Bug

• Use GitHub issue notebook to run a query
• After the results are displayed in the editor, delete the cell
• Output is not cleared

VS Code version: Code - OSS Dev 1.44.0 (Commit unknown, Date unknown)
OS version: Darwin x64 19.2.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz (16 x 2400)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	32.00GB (4.25GB free)
Process Argv	. --no-sandbox
Screen Reader	no
VM	0%

Extensions (1)

Extension	Author (truncated)	Version
vscode-pull-request-github	Git	0.14.0