[transition] which 6 to 8

RDEPS:

• rust-copypasta-ext
• rust-protoc
• rust-which
• prs
• rust-just
• starship
• rust-test-with
• rust-edit
• python-maturin (bug filed)
• rust-broot
• rust-clearscreen
• hx
• precious (bug filed)
• rust-procs
• sccache (bug filed)
• rust-docmatic