nvim nightly breakage, tbl_add_reverse_lookup

[jacobrreed]

Feature will be removed in Nvim 0.12
stack traceback:
        vim/shared.lua: in function 'tbl_add_reverse_lookup'
        ...vim/lazy/nvim-notify/lua/notify/service/notification.lua:19: in main chunk
        [C]: in function 'require'
        ...ocal/share/nvim/lazy/nvim-notify/lua/notify/instance.lua:3: in main chunk
        [C]: in function 'require'
        ...d/.local/share/nvim/lazy/nvim-notify/lua/notify/init.lua:5: in main chunk
        [C]: in function 'require'
        ...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:373: in function <...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:371>
        [C]: in function 'xpcall'
        .../.local/share/nvim/lazy/lazy.nvim/lua/lazy/core/util.lua:113: in function 'try'
        ...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:381: in function 'config'
        ...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:348: in function '_load'
        ...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:191: in function 'load'
        ...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:123: in function 'startup'
        ...rreed/.local/share/nvim/lazy/lazy.nvim/lua/lazy/init.lua:112: in function 'setup'

[pkropachev]

PR: #270