Remove `language-extension-version` script (#51838)

Finn Evers created 

This PR removes the `language-extension-version` script and cleans up
some of the related documentation around updating extensions, as this is
no longer needed and at this point fully automated.


Release Notes:

- N/A

Change summary

extensions/README.md              | 52 +-------------------------------
script/language-extension-version | 29 ------------------
2 files changed, 3 insertions(+), 78 deletions(-)

Detailed changes

extensions/README.md 🔗 

@@ -8,56 +8,10 @@ If you are looking for the Zed extension registry, see the [`zed-industries/exte
 
 Currently, Zed includes support for a number of languages without requiring installing an extension. Those languages can be found under [`crates/languages/src`](https://github.com/zed-industries/zed/tree/main/crates/languages/src).
 
-Support for all other languages is done via extensions. This directory ([extensions/](https://github.com/zed-industries/zed/tree/main/extensions/)) contains a number of officially maintained extensions. These extensions use the same [zed_extension_api](https://docs.rs/zed_extension_api/latest/zed_extension_api/) available to all [Zed Extensions](https://zed.dev/extensions) for providing [language servers](https://zed.dev/docs/extensions/languages#language-servers), [tree-sitter grammars](https://zed.dev/docs/extensions/languages#grammar) and [tree-sitter queries](https://zed.dev/docs/extensions/languages#tree-sitter-queries).
+Support for all other languages is done via extensions. This directory ([extensions/](https://github.com/zed-industries/zed/tree/main/extensions/)) contains some of the officially maintained extensions. These extensions use the same [zed_extension_api](https://docs.rs/zed_extension_api/latest/zed_extension_api/) available to all [Zed Extensions](https://zed.dev/extensions) for providing [language servers](https://zed.dev/docs/extensions/languages#language-servers), [tree-sitter grammars](https://zed.dev/docs/extensions/languages#grammar) and [tree-sitter queries](https://zed.dev/docs/extensions/languages#tree-sitter-queries).
+
+You can find the other officially maintained extensions in the [zed-extensions organization](https://github.com/zed-extensions).
 
 ## Dev Extensions
 
 See the docs for [Developing an Extension Locally](https://zed.dev/docs/extensions/developing-extensions#developing-an-extension-locally) for how to work with one of these extensions.
-
-## Updating
-
-> [!NOTE]
-> This update process is usually handled by Zed staff.
-> Community contributors should just submit a PR (step 1) and we'll take it from there.
-
-The process for updating an extension in this directory has three parts.
-
-1. Create a PR with your changes. (Merge it)
-2. Bump the extension version in:
-
-   - extensions/{language_name}/extension.toml
-   - extensions/{language_name}/Cargo.toml
-   - Cargo.lock
-
-   You can do this manually, or with a script:
-
-   ```sh
-   # Output the current version for a given language
-   ./script/language-extension-version <langname>
-
-   # Update the version in `extension.toml` and `Cargo.toml` and trigger a `cargo check`
-   ./script/language-extension-version <langname> <new_version>
-   ```
-
-   Commit your changes to a branch, push a PR and merge it.
-
-3. Open a PR to [`zed-industries/extensions`](https://github.com/zed-industries/extensions) repo that updates the extension in question
-
-Edit [`extensions.toml`](https://github.com/zed-industries/extensions/blob/main/extensions.toml) in the extensions repo to reflect the new version you set above and update the submodule latest Zed commit.
-
-```sh
-# Go into your clone of the extensions repo
-cd ../extensions
-
-# Update
-git checkout main
-git pull
-just init-submodule extensions/zed
-
-# Update the Zed submodule
-cd extensions/zed
-git checkout main
-git pull
-cd -
-git add extensions.toml extensions/zed
-```

script/language-extension-version 🔗 

@@ -1,29 +0,0 @@
-#!/usr/bin/env bash
-
-set -euox pipefail
-
-if [ "$#" -lt 1 ]; then
-  echo "Usage: $0 <language> [version]"
-  exit 1
-fi
-
-LANGUAGE=$1
-VERSION=${2:-}
-
-EXTENSION_DIR="extensions/$LANGUAGE"
-EXTENSION_TOML="$EXTENSION_DIR/extension.toml"
-CARGO_TOML="$EXTENSION_DIR/Cargo.toml"
-
-if [ ! -d "$EXTENSION_DIR" ]; then
-  echo "Directory $EXTENSION_DIR does not exist."
-  exit 1
-fi
-
-if [ -z "$VERSION" ]; then
-  grep -m 1 'version =' "$EXTENSION_TOML" | awk -F\" '{print $2}'
-  exit 0
-fi
-
-sed -i '' -e "s/^version = \".*\"/version = \"$VERSION\"/" "$EXTENSION_TOML"
-sed -i '' -e "s/^version = \".*\"/version = \"$VERSION\"/" "$CARGO_TOML"
-cargo update --workspace