python: add Python 3.13 testing in CI #1280

Job	Run time
Test Minimum Positron IPyKernel Dependencies (ubuntu-latest, 3.8)	4m 34s
Test Positron IPyKernel (macos-latest, 3.9)	2m 19s
Lint	2m 47s
Test Positron IPyKernel (windows-latest, 3.10)	3m 16s
Test Positron IPyKernel (ubuntu-latest, 3.11)	2m 42s
Python Tests (ubuntu-latest, 3.8)	1m 41s
Python Tests (ubuntu-latest, 3.13)	1m 45s
Test Positron IPyKernel (ubuntu-latest, 3.12)	3m 15s
Test Positron IPyKernel (ubuntu-latest, 3.13)	2m 51s
Check Python types	2m 59s
Test TypeScript (ubuntu-latest, 3.x, ts-unit)	2m 56s
Test TypeScript (ubuntu-latest, 3.x, functional)	1m 43s
Test TypeScript (macos-latest, 3.x, ts-unit)	3m 17s
Test TypeScript (macos-latest, 3.x, venv)	3m 20s
Test TypeScript (macos-latest, 3.x, single-workspace)	3m 0s
Test TypeScript (macos-latest, 3.x, debugger)	2m 18s
Test TypeScript (macos-latest, 3.x, functional)	1m 30s
Test TypeScript (macos-latest, 3.x, smoke)	3m 29s
Test TypeScript (windows-latest, 3.x, ts-unit)	4m 57s
Test TypeScript (windows-latest, 3.x, functional)	3m 59s
	58m 38s

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