fix: Fixed missing .pub-cache folder creation in .gitlab-ci.yml

.gitlab-ci.yml

@@ -84,6 +84,8 @@ pub-dev:
         echo "Missing PUB_DEV_PUBLISH_EXPIRATION environment variable"
         exit 1
       fi
+      
+      mkdir -p ~/.pub-cache
 
       cat <<EOF > ~/.pub-cache/credentials.json
       {