python/ci: adjust CI testing for python 3.8 (#5782) #1181

Job	Run time
Lint	1m 39s
Check Python types	3m 7s
Test Positron IPyKernel (macos-latest, 3.9)	2m 3s
Python Tests (ubuntu-latest, 3.8)	1m 45s
Test Positron IPyKernel (windows-latest, 3.10)	8m 35s
Python Tests (ubuntu-latest, 3.12)	1m 40s
Test Minimum Positron IPyKernel Dependencies (ubuntu-latest, 3.8)	3m 22s
Test Positron IPyKernel (ubuntu-latest, 3.11)	3m 3s
Test Positron IPyKernel (ubuntu-latest, 3.12)	2m 55s
Test TypeScript (ubuntu-latest, 3.x, ts-unit)	3m 5s
Test TypeScript (ubuntu-latest, 3.x, functional)	1m 57s
Test TypeScript (macos-latest, 3.x, ts-unit)	3m 1s
Test TypeScript (macos-latest, 3.x, venv)	3m 28s
Test TypeScript (macos-latest, 3.x, single-workspace)	3m 6s
Test TypeScript (macos-latest, 3.x, debugger)	2m 25s
Test TypeScript (macos-latest, 3.x, functional)	1m 36s
Test TypeScript (macos-latest, 3.x, smoke)	4m 15s
Test TypeScript (windows-latest, 3.x, ts-unit)	5m 33s
Test TypeScript (windows-latest, 3.x, functional)	4m 37s
	1h 1m 12s

Provide feedback