Remove the optional salsa dependency from the AST crate #35713

Job	Run time
mkdocs	3m 3s
Determine changes	12s
cargo fmt	19s
python package	1m 37s
pre-commit	45s
benchmarks	5m 0s
cargo build (release)	4m 58s
cargo clippy	2m 11s
cargo build (msrv)	4m 37s
cargo fuzz	5m 8s
cargo shear	27s
cargo test (linux)	4m 31s
cargo test (wasm)	1m 42s
cargo test (windows)	9m 23s
formatter instabilities and black similarity	4m 9s
test scripts	1m 10s
Fuzz the parser	6m 51s
ecosystem	14m 13s
test ruff-lsp	34s
	1h 10m 50s

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