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/scripts/setup-windows.ps1

@@ -179,7 +179,7 @@ if (-not (Ensure-Command 'cargo')) {
 Write-Host "==> Configuring Rust toolchain per rust-toolchain.toml" -ForegroundColor Cyan
 
 # Pin to the workspace toolchain and install components
-$toolchain = '1.93.0'
+$toolchain = '1.95.0'
 & rustup toolchain install $toolchain --profile minimal | Out-Host
 & rustup default $toolchain | Out-Host
 & rustup component add clippy rustfmt rust-src --toolchain $toolchain | Out-Host