fix: args behind `--` is not forwarded to cargo build

[zjp-CN]

As per the usage, stuff behind -- are passed to cargo build, so this commit fixes this.

cargo lockbud [options] [...] [--] [<program/test suite options>...]

Other [options] are the same as cargo build. Everything after the second "--" verbatim to the program.

[zjp-CN]

The usage is a bit confusing. It says

• Other [options] are the same as cargo build. So it implies cargo lockbud [options] [...] [--] ... can accept cargo lockbud [lockbud options] [cargo build options] [...] [--] .... Actually this doesn't work either.
• Everything after the second "--" What does the first -- do then?

I think the usage makes sense as follows, and this PR is trying to achieve this

cargo lockbud [args for lockbud] [--] [args for cargo build]

e.g.

cargo +nightly-2024-05-21 lockbud -k all -- --target riscv64gc-unknown-none-elf
cargo +nightly-2024-05-21 lockbud -k all -- --target riscv64gc-unknown-none-elf -- args-to-the-compiled-binary

p.s. `cargo +nightly-2024-05-21` is from cargo, not from cargo lockbud. It demonstrates
the canonical command to be used as real detection on projects.

[BurtonQin]

Thanks for your fixing. There is indeed something wrong with my previous cargo parameter parsing logic.