Uprev Rust toolchain pins to 1.95.0 (#24684)

## Summary
- Bump the workspace Rust toolchain from `1.93.0` to `1.95.0` across
Cargo, Bazel, CI, release workflows, devcontainers, and the Codex
environment config.
- Refresh `MODULE.bazel.lock` so the Bazel Rust toolchain artifacts
match the new version.
- Leave purpose-specific toolchains unchanged, including the
`argument-comment-lint` nightly and the upstream `rusty_v8` `1.91.0`
build pin.
- Includes fixes for new lints from `just fix` and a few codex-authored
fixes for lints without a suggestion.

codex-rs/app-server/src/outgoing_message.rs

@@ -456,8 +456,8 @@ impl OutgoingMessageSender {
     ) -> Vec<ServerRequest> {
         let request_id_to_callback = self.request_id_to_callback.lock().await;
         let mut requests = request_id_to_callback
-            .iter()
-            .filter_map(|(_, entry)| {
+            .values()
+            .filter_map(|entry| {
                 (entry.thread_id == Some(thread_id)).then_some(entry.request.clone())
             })
             .collect::<Vec<_>>();