Log Message:
lang/rust: remove use of patchelf, as suggested by riastradh@

This was a misguided attempt at dealing with
https://github.com/rust-lang/rust/issues/133629
which was triggered by trying to run the stage1 rust
compiler from within the build tree, and this use
of patchelf did in fact not fix this problem.
Ref. also
https://mail-index.netbsd.org/pkgsrc-changes/2025/04/02/msg320497.html