circleci: drop scan-build from the jobs to run
circleci: drop scan-build from the jobs to run

Scan-build is at the point where it gives us too many false positives to be
reliable and they're not easily fixable other than sprinkling
"ignore_clang_sa_mem_leak" comments all over the source.

This caused us to drop F29 from the CI earlier, see 1225f421c0a50083, but
really we just shouldn't use something that's so unreliable as part of our CI.

The main issue continues to be the use of __attribute__((cleanup)) but others
give us false positives too.

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

libratbag/libratbag,whot/libratbag,whot/libratbag,libratbag/libratbag,whot/libratbag,libratbag/libratbag