ci(deps): update rust

Author: Meshiest

.github/workflows/pr.yml

@@ -5,8 +5,8 @@ on:
 env:
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: 1
-  # https://releases.rs/docs/1.83.0/ release date
-  NIGHTLY_TOOLCHAIN: nightly-2025-02-20
+  # https://releases.rs/docs/1.88.0/ release date
+  NIGHTLY_TOOLCHAIN: nightly-2025-06-26
 
 # Cancel in progress workflows on pull_requests.
 # https://docs.github.com/en/actions/using-jobs/using-concurrency#example-using-a-fallback-value