Cirrus: Build static podman-remote

Prior to this commit, the "Static Build" task only produced a
`bin/podman`.  Update this to also include a `bin/podman-remote`
binary.

Update the pr-should-include-tests checker to ignore the `nix`
directory, which isn't applicable.

Lastly, restore the static build task to 'required' for CI success.
Leaving the comment inplace in case it needs to be bypassed in the
future on short notice.

Signed-off-by: Chris Evich <cevich@redhat.com>

contrib/cirrus/pr-should-include-tests

@@ -39,6 +39,7 @@ filtered_changes=$(git diff --name-status $base $head |
                        egrep -v  '^contrib/'          |
                        egrep -v  '^docs/'             |
                        egrep -v  '^hack/'             |
+                       egrep -v  '^nix/'              |
                        egrep -v  '^vendor/'           |
                        egrep -v  '^version/')
 if [[ -z "$filtered_changes" ]]; then