Update nerd fonts to 3.0

[anstadnik]

After https://github.com/ryanoasis/nerd-fonts/releases/tag/v3.0.0 certain icons were deprecated.

[vinnydiehl]

Thanks for this, I was about to do this myself but my spidey sense was tingling and I checked the PRs. I'd love to see this merged, we would need to update a few more documents:

󰁔 lua  grep -rn  .                                               
./symbols-outline.nvim/doc/symbols-outline.txt:90:        Module = { icon = "", hl = "@namespace" },
./symbols-outline.nvim/lua/symbols-outline/config.lua:42:    Module = { icon = '', hl = '@namespace' },
./symbols-outline.nvim/README.md:68:    Module = { icon = "", hl = "@namespace" },

Is this something you're willing to take on, or would you like some help?

[anstadnik]

Done. Not sure about merging though, I assume @simrat39 is not active

[sxzebra]

tested and works