Kubernetes step jobs with a `run:` block were invoked via
`/bin/sh -c <script>`. On debian-family base images that resolves to
dash, which rejects `set -o pipefail` ("Illegal option") and other
bashisms (arrays, process substitution, `{1..10}`). The first line of
nearly every real CI script relies on `set -euo pipefail`, so the
steps were failing with exit code 2 before running a single command.
Switch to `/bin/bash -c` so `run:` scripts can rely on the bash
feature set. Containers that lack bash should use the explicit
`command:` form instead.
Pure formatting pass from `cargo fmt --all`. No logic changes. Separating
this out so the 1.9 release feature commits that follow show only their
intentional edits.
