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/memories/write/src/phase1.rs

@@ -206,7 +206,7 @@ async fn run_jobs(
     claimed_candidates: Vec<codex_state::Stage1JobClaim>,
     stage_one_context: StageOneRequestContext,
 ) -> Vec<JobResult> {
-    futures::stream::iter(claimed_candidates.into_iter())
+    futures::stream::iter(claimed_candidates)
         .map(|claim| {
             let context = Arc::clone(&context);
             let config = Arc::clone(&config);