macos pkginstaller: do not fail when podman-mac-helper fails

Make sure we can install podman even when the podman-mac-helper install
command fails. This used to be the behavior but commit bae07b6 caused
the regression because the binary now returns 1 as exit code on errors.

[NO NEW TESTS NEEDED] I am not sure if we can test the install step in
CI.

Fixes containers#17910

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

contrib/pkginstaller/scripts/postinstall

@@ -7,4 +7,5 @@ echo "/opt/podman/bin" > /etc/paths.d/podman-pkg
 ln -s /opt/podman/bin/podman-mac-helper /opt/podman/qemu/bin/podman-mac-helper
 ln -s /opt/podman/bin/gvproxy /opt/podman/qemu/bin/gvproxy
 
-/opt/podman/bin/podman-mac-helper install
+# make sure to ignore errors, this is not a hard requirement to use podman
+/opt/podman/bin/podman-mac-helper install || :