Add public API event for kernel post-initialization #17418

Job	Run time
Build VSIX	1m 15s
Lint	2m 3s
cancel_previous_runs	2s
Type Script Tests (ubuntu-latest, ts-unit)	1m 20s
Tests (raw, python, 3.10, ^[^@]+$\|@mandatory\|@kernelCore\|@python\|@jupyter, ubuntu-latest)	5m 55s
Type Script Tests (windows-latest, ts-unit)	5m 41s
Tests (raw, python, 3.10, @widgets, ubuntu-latest)	4m 46s
Tests (raw, python, 3.10, @iw, ubuntu-latest)	4m 6s
Tests (raw, python, 3.10, @webview\|@export\|@lsp\|@variableViewer, ubuntu-latest)	4m 14s
Tests (raw, python, 3.10, @debugger, ubuntu-latest)	3m 18s
Tests (remote, python, 3.10, ^[^@]+$\|@mandatory, ubuntu-latest)	3m 43s
Tests (web, python, 3.10, ^[^@]+$\|@mandatory, ubuntu-latest)	4m 51s
Tests (raw, python, 3.10, ^[^@]+$\|@mandatory, windows-latest)	6m 36s
Tests (raw, python, 3.10, @widgets, ubuntu-latest, 8)	4m 34s
Tests (remote, python, 3.10, @widgets, ubuntu-latest, 8)	5m 24s
Tests (raw, conda, 3.10, ^[^@]+$\|@mandatory\|@python, ubuntu-latest)	3m 42s
Tests (raw, noPython, @nonPython, ubuntu-latest)	1m 40s
Tests (remote, python, 3.10, @kernelCore, ubuntu-latest)	4m 3s
Smoke tests (ubuntu-latest, 3.10)	1m 40s
Smoke tests (windows-latest, 3.10)	3m 40s
Smoke tests (macos-latest, 3.10)	1m 22s
	1h 13m 55s

Provide feedback