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/hooks/src/schema.rs

@@ -707,7 +707,7 @@ fn canonicalize_json(value: &Value) -> Value {
         Value::Array(items) => Value::Array(items.iter().map(canonicalize_json).collect()),
         Value::Object(map) => {
             let mut entries: Vec<_> = map.iter().collect();
-            entries.sort_by(|(left, _), (right, _)| left.cmp(right));
+            entries.sort_by_key(|(key, _)| *key);
             let mut sorted = Map::with_capacity(map.len());
             for (key, child) in entries {
                 sorted.insert(key.clone(), canonicalize_json(child));