main/p11-kit: Ensure trust_paths is set
During the upgrade from `0.23.18.1-r0` to `0.23.20-r0` in commit 7aef1583, the build system was changed from autotools to meson, but the `--with-trust-paths` option didn't get ported over to the meson equivalent. This caused commands, like `trust list`, to return no results, which causes Java issues due to `/etc/ssl/certs/java/cacerts` not being updated properly (#11185). This commit adds the meson `trust_paths` build variable so that p11-kit can find the proper CA certs file. Signed-off-by:Andrew Gunnerson <andrew.gunnerson@us.ibm.com>