fix(icons): replace deprecated nerd-fonts icons

[carlosala]

• PR Description
  Replace deprecated nerd-fonts icons from v3 on.

• Please check if the PR fulfills these requirements

• Cheatsheets are up-to-date (run go run scripts/cheatsheet/main.go generate)
• Code has been formatted (see here)
• Tests have been added/updated (see here for the integration test guide)
• Text is internationalised (see here)
• Docs (specifically docs/Config.md) have been updated if necessary
• You've read through your own file changes for silly mistakes etc

[David-Else]

Brilliant! This fixes the super annoying font problems I have had with v2.3.3 Symbols-2048-em Nerd Font Complete Mono.ttf in Kitty.

I tried copying and pasting the new and old from this pull request in the terminal, and it looks much better:

Is this the same as #2593, different author @jtrv ?

Also, check out this related issue #2236, which will hopefully be closable when this is merged.

[jtrv]

@David-Else In my PR I changed the nerdfont character in the comment next to the code point in the same way this PR does, but the code points here are invalid. When I tried using the correct code points on my branch they didn't seem to be read correctly, so I've closed my pr until I can figure out how to get it working properly.

[gotgenes]

I made an alternative PR that uses higher order unicode code points. #2604

[carlosala]

Closed in favour of #2604