Bump docker-distribution-pruner to v0.3.0

This version upgrade:

* Requires Go 1.22 and higher
* Bumps an outdated golang.org/x/net version

This project is defunct, but some scanners will might find that CVEs
from the old dependency.

Changelog: changed

config/software/docker-distribution-pruner.rb

@@ -15,7 +15,7 @@
 # limitations under the License.
 #
 require "#{Omnibus::Config.project_root}/lib/gitlab/version"
-version = Gitlab::Version.new('docker-distribution-pruner', '0.2.0')
+version = Gitlab::Version.new('docker-distribution-pruner', '0.3.1')
 name 'docker-distribution-pruner'
 default_version version.print