fix(workspace): exclude zed-storybook from workspace

Added zed-storybook to workspace.exclude to prevent cargo from
treating it as a workspace member. This allows Zed to build the
extension independently.

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 members = [".", "xtask"]
-exclude = ["tree-sitter-storybook"]
+exclude = ["tree-sitter-storybook", "zed-storybook"]
 
 [package]
 name = "storybook"