Bump `alacritty_terminal` repo SHA (#59445)

See
https://github.com/zed-industries/alacritty/commit/4c129667ce56611becdc82de6e28218c80e2e88f.
The main change here is making `set_nonblocking` return `Result` rather
than panicking.

Closes FR-78.

Release Notes:

- N/A
1bc9d8e80eNeel committed on 6/17/2026, 7:12:24 PM· committed by GitHubparentf4c621b
2 files changedLine totals unavailable