fix(atuin): remove Atuin

pkgx has some issues that are leading to users opening more issues on the
Atuin repo

See:

1. https://github.com/atuinsh/atuin/issues/1765
2. https://github.com/atuinsh/atuin/issues/1809

Given that that's two issues almost within a week of each other, there
are likely many more people having a sub-par experience and not even
realising that this is due to pkgx.

I'm also concerned about three other things

1. Atuin being listed under a non-canonical name (atuin.sh, rather than
   just atuin)
2. Atuin having been misrepresented in the past (see
   https://github.com/pkgxdev/pantry/issues/5358)
3. [Some weird crypto thing](https://connortumbleson.com/2024/02/26/the-disappointing-tea-xyz/), which seems related?

It also looks like I'm not alone here:

1. https://github.com/pkgxdev/pantry/pull/5360
2. https://github.com/pkgxdev/pantry/issues/5359

I'd rather avoid Atuin being distributed by pkgx, at least for now.

projects/atuin.sh/package.yml

@@ -1,30 +0,0 @@
-distributable:
-  url: git+https://github.com/atuinsh/atuin
-  ref: ${{version.tag}}
-
-display-name: Atuin
-
-versions:
-  github: atuinsh/atuin
-
-build:
-  dependencies:
-    rust-lang.org: '>=1.65'
-    rust-lang.org/cargo: '*'
-  script:
-    - cargo install $ARGS
-  env:
-    ARGS:
-      - --path=atuin
-      - --locked
-      - --root={{prefix}}
-
-provides:
-  - bin/atuin
-
-test:
-  script:
-    - atuin init bash | grep 'Add it to the bash history'
-    - atuin --version | grep ${{version.tag}}
-  env:
-    ATUIN_SESSION: random