Fix fifo files hanging the project wide search (#16039)

Release Notes:

- Fixed the issue related to the project wide search being stuck when
project contains .fifo files
- Might potentially solve the following issue
https://github.com/zed-industries/zed/issues/7360

crates/collab/migrations.sqlite/20221109000000_test_schema.sql

@@ -86,6 +86,7 @@ CREATE TABLE "worktree_entries" (
     "is_ignored" BOOL NOT NULL,
     "is_deleted" BOOL NOT NULL,
     "git_status" INTEGER,
+    "is_fifo" BOOL NOT NULL,
     PRIMARY KEY(project_id, worktree_id, id),
     FOREIGN KEY(project_id, worktree_id) REFERENCES worktrees (project_id, id) ON DELETE CASCADE
 );