Rollup merge of #83820 - petrochenkov:nolinkargs, r=nagisa

Remove attribute `#[link_args]`

Closes https://github.com/rust-lang/rust/issues/29596

The attribute could always be replaced with `-C link-arg`, but cargo didn't provide a reasonable way to pass such flags to rustc.
Now cargo supports `cargo:rustc-link-arg*` directives in build scripts (https://doc.rust-lang.org/cargo/reference/unstable.html#extra-link-arg), so this attribute can be removed.