Simplify relibc install steps

1 job for cbindgen in 56 minutes and 36 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #25718
img

00:56:36

 
Name Stage Failure
failed
img Test
make[2]: *** [build/bootloader] Error 1
Makefile:28: recipe for target 'build/bootloader' failed
make[2]: Leaving directory '/builds/gmacd/redox/bootloader-coreboot'
make[1]: *** [bootloader-coreboot/build/bootloader] Error 2
mk/disk.mk:32: recipe for target 'bootloader-coreboot/build/bootloader' failed
make[1]: Leaving directory '/builds/gmacd/redox'
Makefile:65: recipe for target 'ci-img' failed
make: *** [ci-img] Error 2
ERROR: Job failed: exit code 1