[CI/Build] Add shell script linting using shellcheck

[russellb]

b70364a format.sh: run shellcheck on all shell scripts
1077fda Make shellcheck run cleanly

commit b70364a
Author: Russell Bryant rbryant@redhat.com
Date: Tue Aug 27 13:32:40 2024 -0400

format.sh: run shellcheck on all shell scripts

This runs the `shellcheck` linter against all shell scripts in the
repo. Download the tool automatically if it's not found, at least on
Linux+x86_64.

Also run shellcheck in CI.

Signed-off-by: Russell Bryant <rbryant@redhat.com>

commit 1077fda
Author: Russell Bryant rbryant@redhat.com
Date: Mon Aug 26 13:16:56 2024 -0400

Make shellcheck run cleanly

This fixes a bunch of warnings from shellcheck. A sample of things
addressed here include:

- Quote variables to avoid accidental globbing or variable splitting.
  For example, as a best practice, `cd ${foo}` should be written as
  `cd "${foo}"`. Otherwise, a directory with a space in the name would
  break in the script.

- Remove unused variables and fix a variable name typo.

- Simplify error checking: `if command` instead of
  `command; if [ $?  -eq 0 ]`.

- Remove an unnecessary echo, i.e. `$(echo $(command) | foo)` can
  instead be `$(command | foo)`.

- Specify `#!/bin/bash` in scripts that did not include it.

Note that I left one script ignored for the moment, as the required
change seemed like it wraranted its own separate commit.

Signed-off-by: Russell Bryant <rbryant@redhat.com>

[github-actions]

👋 Hi! Thank you for contributing to the vLLM project.
Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which consists a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of default ones by unblocking the steps in your fast-check build on Buildkite UI.

Once the PR is approved and ready to go, please make sure to run full CI as it is required to merge (or just use auto-merge).

To run full CI, you can do one of these:

• Comment /ready on the PR
• Add ready label to the PR
• Enable auto-merge.

🚀

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @russellb.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[DarkLight1337]

Sorry for missing this!

[russellb]

Sorry for missing this!

@DarkLight1337 no problem - PR queue is quite busy! I'm trying to help some where I can with reviews, and not just adding things to review :)

feel free to tag me on anything you'd like me to review anytime!