Fix faulty validation of subtask names in sequence tasks (#219) #1176

Job	Run time
Check coding standards	31s
Run tests (Ubuntu, 3.8)	1m 47s
Run tests (Ubuntu, 3.9)	1m 35s
Run tests (Ubuntu, 3.10)	2m 3s
Run tests (Ubuntu, 3.11)	1m 41s
Run tests (Ubuntu, 3.12)	1m 36s
Run tests (MacOS, 3.8)	2m 20s
Run tests (MacOS, 3.9)	1m 41s
Run tests (MacOS, 3.10)	1m 26s
Run tests (MacOS, 3.11)	1m 14s
Run tests (MacOS, 3.12)	1m 13s
Run tests (Windows, 3.9)	3m 8s
Run tests (Windows, 3.10)	2m 59s
Run tests (Windows, 3.11)	2m 42s
Run tests (Windows, 3.12)	3m 18s
Build distribution	10s
Upload release to PyPI	0s
Upload homebrew formula	0s
Sign the Python 🐍 distribution 📦 with Sigstore and upload them to GitHub Release	0s
	29m 24s

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