Fix github-cli toolbox build

Author: jometzner

dot_toolboxes/github-cli/Containerfile

@@ -2,4 +2,4 @@ FROM quay.io/jometzner/toolbox-base:42
 
 RUN dnf install dnf5-plugins
 RUN dnf config-manager addrepo --from-repofile=https://cli.github.com/packages/rpm/gh-cli.repo
-RUN dnf install gh --repo gh-cli
+RUN dnf install -y gh --repo gh-cli && dnf clean all