Enable bootstrap container for CentOS Stream 10

Since CentOS Stream 10 hasn't been released yet, the container image
exists but is using the tag stream10-development instead of stream10.
At some point (probably the release announcement) it will start using
the stream10 tag.  This image is "ready" (i.e. `dnf builddep` is
pre-installed).

mock-core-configs/etc/mock/templates/centos-stream-10.tpl

@@ -5,8 +5,8 @@ config_opts['package_manager'] = 'dnf'
 config_opts['extra_chroot_dirs'] = [ '/run/lock', ]
 config_opts['description'] = 'CentOS Stream 10'
 
-config_opts['use_bootstrap_image'] = False
-config_opts['bootstrap_image'] = 'quay.io/centos/centos:stream10'
+config_opts['bootstrap_image'] = 'quay.io/centos/centos:stream10-development'
+config_opts['bootstrap_image_ready'] = True
 
 config_opts['dnf.conf'] = """
 [main]