FileExt methods cause compiler warnings on rust 1.84

[eric-seppanen]

Using the lock methods from fs_std cause rustc warnings on rust 1.84:

use fs4::fs_std::FileExt;

pub fn read_file(filename: &str) -> String {
    let mut file = std::fs::File::open(filename).unwrap();
    file.lock_shared().unwrap();
    let mut data = String::new();
    file.read_to_string(&mut data).unwrap();
    data
}

$ cargo +beta-2024-11-27 check

warning: a method with this name may be added to the standard library in the future
  --> src/lib.rs:10:10
   |
10 |     file.lock_shared().unwrap();
   |          ^^^^^^^^^^^
   |
   = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
   = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
   = help: call with fully qualified syntax `lock_shared(...)` to keep using the current method
   = note: `#[warn(unstable_name_collisions)]` on by default

The name collision happens for lock_shared, try_lock_shared, and unlock, which are tracked by the file_lock feature (rust-lang/rust#130994).