fix: delete neo-tree buffers created by :mksession#748

cseickel merged 2 commits intonvim-neo-tree:mainnvim-neo-tree/neo-tree.nvim:mainfrom

nhat-vo:740-mksession-containing-neotree-buffernhat-vo/neo-tree.nvim:740-mksession-containing-neotree-bufferCopy head branch name to clipboard