Completely drop `RootModel` from `types` module #206

Job	Run time
checks / pre-commit	36s
checks / readme-snippets	16s
checks / test (3.11, locked, windows-latest)	2m 32s
checks / test (3.10, lowest-direct, windows-latest)	2m 25s
checks / test (3.12, locked, windows-latest)	3m 28s
checks / test (3.12, lowest-direct, windows-latest)	3m 22s
checks / test (3.10, lowest-direct, ubuntu-latest)	45s
checks / test (3.11, locked, ubuntu-latest)	47s
checks / test (3.13, lowest-direct, windows-latest)	2m 28s
checks / test (3.13, lowest-direct, ubuntu-latest)	44s
checks / test (3.11, lowest-direct, ubuntu-latest)	47s
checks / test (3.10, locked, windows-latest)	2m 23s
checks / test (3.11, lowest-direct, windows-latest)	3m 21s
checks / test (3.10, locked, ubuntu-latest)	49s
checks / test (3.12, lowest-direct, ubuntu-latest)	52s
checks / test (3.12, locked, ubuntu-latest)	53s
checks / test (3.13, locked, ubuntu-latest)	47s
checks / test (3.13, locked, windows-latest)	2m 34s
checks / test (3.14, lowest-direct, windows-latest)	2m 12s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 8s
checks / test (3.14, locked, ubuntu-latest)	2m 10s
checks / test (3.14, locked, windows-latest)	3m 21s
all-green	4s
	38m 44s

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