tests: Ignore symbol-versions in nm output

The Debian 11 toolchain produces them like this.

Signed-off-by: Simon McVittie <smcv@collabora.com>
6 jobs for master in 8 minutes and 20 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
manual build:arch #79771
allowed to fail manual
passed build:asan #79767

00:03:28

passed build:bionic #79770

00:08:18

passed build:buster #79769

00:07:51

passed build:stretch #79768

00:08:19

passed build:ubsan #79766

00:03:25