Bump all crates to 1.70 MSRV. #1299

Job	Run time
Run JS linters	2m 17s
Check fuzz targets	1m 9s
Check lint and rustfmt	3m 38s
Check rustdoc WASM target	55s
Run tests	6m 27s
Python tests and maturin build (3.9)	36s
WASM tests	1m 27s
Python tests and maturin build (3.10)	30s
Python tests and maturin build (3.11)	28s
pre-publish checks	0s
All CI stages	2s
pre-publish checks	0s
publish trustfall_filetests_macros	0s
publish trustfall_core	0s
publish python trustfall	0s
publish trustfall_derive	0s
publish trustfall	0s
publish trustfall_stubgen	0s
	17m 29s

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