Bootstrap: Initialized submodules no longer eagerly updated by running x.py

[bjorn3]

maybe_update_submodules should already do this, but

rust/src/bootstrap/lib.rs

Lines 628 to 635 in c4693bc

	let mut bootstrap_submodules: Vec<&str> = vec![
	"src/tools/rust-installer",
	"src/tools/cargo",
	"src/tools/rls",
	"src/tools/miri",
	"library/backtrace",
	"library/stdarch",
	];

hasn't been kept in sync with the removal of identical functionality from x.py. Also rust-analyzer is only updated when vendoring is enabled.

[matthiaskrgr]

I think this was caused by #97513