We're currently failing the auoptmated security review on snapcraft
because the lotus binary has the execstack value set:
https://linux.die.net/man/8/execstack
This commit passes the appropriate flags to ld to disable the execstack
flag when building the binaries for snapcraft:
https://linux.die.net/man/1/ld
We may want to consider disabling this as part of the main build.
Research seems to indicate that allow the executable stack can lead to
security issues, but I am not enough of a security expert to know for
sure what the right call here is:
https://f0rm2l1n.github.io/2022-04-02-What-is-happended-to-execstack/
