Omit gitignored files from context file picker (#23777)

In both `thread` and `prompt editor` the context file picker, gitignored
files are hidden (as expected) when searching files by path, but they
are still shown initially as you create the file picker.

Plus, selecting gitignored files in the `prompt editor` is bugged and
collapses everything.

This PR settles on not showing gitignored files to solve these
inconsistencies.

Release Notes:

- Fix gitignored files filter occasionally not working in context file
picker.

crates/assistant_slash_commands/Cargo.toml

@@ -45,6 +45,7 @@ toml.workspace = true
 ui.workspace = true
 util.workspace = true
 workspace.workspace = true
+worktree.workspace = true
 
 [dev-dependencies]
 env_logger.workspace = true

crates/assistant_slash_commands/src/file_command.rs

@@ -20,6 +20,7 @@ use std::{
 use ui::prelude::*;
 use util::ResultExt;
 use workspace::Workspace;
+use worktree::ChildEntriesOptions;
 
 pub struct FileSlashCommand;
 
@@ -42,7 +43,13 @@ impl FileSlashCommand {
                 .chain(project.worktrees(cx).flat_map(|worktree| {
                     let worktree = worktree.read(cx);
                     let id = worktree.id();
-                    worktree.child_entries(Path::new("")).map(move |entry| {
+                    let options = ChildEntriesOptions {
+                        include_files: true,
+                        include_dirs: true,
+                        include_ignored: false,
+                    };
+                    let entries = worktree.child_entries_with_options(Path::new(""), options);
+                    entries.map(move |entry| {
                         (
                             project::ProjectPath {
                                 worktree_id: id,