Auto merge of #45423 - durka:update-jobserver, r=Mark-Simulacrum

update jobserver version to work around macos bug

Update `jobserver` crate to fix rust-lang/cargo#4643, a panic which can't happen according to `libc::poll`'s man page but was nevertheless reported on macOS 10.9 and 10.10.

r? @alexcrichton

Author: bors