wstunnel: update to 8.5.4

[cinerea0]

Testing the changes

• I tested the changes in this PR: YES

[cinerea0]

Version 8.5.2 (the latest as of this comment) requires Rust 1.75.

[leahneukirchen]

Sure it requires?

[cinerea0]

This is the error I get when compiling the new latest version (8.5.4):

error[E0658]: use of unstable library feature 'file_set_times'
  --> src/tunnel/tls_reloader.rs:89:26
   |
89 |             let _ = file.set_modified(SystemTime::now()).map_err(|err| {
   |                          ^^^^^^^^^^^^
   |
   = note: see issue #98245 <https://github.com/rust-lang/rust/issues/98245> for more information

That feature was stabilized in Rust 1.75. However, it can be made to compile by commenting out one small block that supports an edge case (see erebe/wstunnel#209 (comment)). What do you think?

[leahneukirchen]

sgtm, even if 1.75 will land soon i assume.