gen_rust_project doesn't work with bzlmod

[granaghan]

rules_rust/tools/rust_analyzer/lib.rs

Line 69 in a58d952

"{workspace_name}/rust/private/rust_analyzer_detect_sysroot.rust_analyzer_toolchain.json"

The "~" added to modules causes a failure here when it looks for "rules_rust~/rust/private/rust_analyzer_detect_sysroot.rust_analyzer_toolchain.json" in runfiles. Hacking it up to remove the "~" seemed to fix it.

[dzbarsky]

Fixing this depends on #2566. Hardcoding rules_rust is not correct in the face of repo remapping.