The kube-aggregator itself only depends on the following runtime
libraries when linking dynamically:
```
> ldd _output/bin/kube-aggregator
linux-vdso.so.1 (0x00007fff1616f000)
libpthread.so.0 => /nix/store/4nlgxhb09sdr51nc9hdm8az5b08vzkgx-glibc-2.35-163/lib/libpthread.so.0 (0x00007fad9339a000)
libc.so.6 => /nix/store/4nlgxhb09sdr51nc9hdm8az5b08vzkgx-glibc-2.35-163/lib/libc.so.6 (0x00007fad93000000)
/nix/store/4nlgxhb09sdr51nc9hdm8az5b08vzkgx-glibc-2.35-163/lib/ld-linux-x86-64.so.2 => /nix/store/4nlgxhb09sdr51nc9hdm8az5b08vzkgx-glibc-2.35-163/lib64/ld-linux-x86-64.so.2 (0x00007fad933a1000)
```
We now move the kube-aggregator to become a static binary as well to
achieve maximum portability.
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
3698434d6b