Extract Zig support into an extension (#9893)

This PR extracts Zig support into an extension and removes the built-in
Zig support from Zed.

There's a small workaround necessary in order for us to set the file
permissions on the `zls` binary so that it can be run. Eventually we'll
want to build this into the extension API, but for now we're just
hard-coding it on the host side.

Release Notes:

- Removed built-in support for Zig, in favor of making it available as
an extension. The Zig extension will be suggested for download when you
open a `.zig` file.

Cargo.lock

@@ -5330,7 +5330,6 @@ dependencies = [
  "tree-sitter-typescript",
  "tree-sitter-vue",
  "tree-sitter-yaml",
- "tree-sitter-zig",
  "unindent",
  "util",
  "workspace",
@@ -10508,15 +10507,6 @@ dependencies = [
  "tree-sitter",
 ]
 
-[[package]]
-name = "tree-sitter-zig"
-version = "0.0.1"
-source = "git+https://github.com/maxxnino/tree-sitter-zig?rev=0d08703e4c3f426ec61695d7617415fff97029bd#0d08703e4c3f426ec61695d7617415fff97029bd"
-dependencies = [
- "cc",
- "tree-sitter",
-]
-
 [[package]]
 name = "try-lock"
 version = "0.2.4"
@@ -12635,6 +12625,13 @@ dependencies = [
  "zed_extension_api 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "zed_zig"
+version = "0.0.1"
+dependencies = [
+ "zed_extension_api 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "zeno"
 version = "0.2.3"