ci: add maintenance workflow (#643) [skip ci]

.github/workflows/maintenance/delete_ghcr_dangling_images.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+set -e
+
+# Simple script to remove dangling images from GHCR
+# You need to be logged to 'gh' first.
+
+# package_name syntax. i.e: jellyfin-vue
+container="$1"
+temp_file="ghcr_prune.ids"
+rm -rf $temp_file
+
+echo "Fetching dangling images from GHCR..."
+gh api /user/packages/container/${container}/versions --paginate > $temp_file
+
+ids_to_delete=$(cat "$temp_file" | jq -r '.[] | select(.metadata.container.tags==[]) | .id')
+
+if [ "${ids_to_delete}" = "" ]
+then
+	echo "There are no dangling images to remove for this package"
+	exit 0
+fi
+
+echo -e "\nDeleting dangling images..."
+while read -r line; do
+	id="$line"
+	## Workaround for https://github.com/cli/cli/issues/4286 and https://github.com/cli/cli/issues/3937
+	echo -n | gh api --method DELETE /user/packages/container/${container}/versions/${id} --input -
+	echo Dangling image with ID $id deleted successfully
+done <<< $ids_to_delete
+
+rm -rf $temp_file
+echo -e "\nAll the dangling images have been removed successfully"
+exit 0