ci: factor sanitizer package lists

[ulises-jeremias]

This is a small incremental cleanup for #27841.

Summary

• Move repeated Linux sanitizer apt package lists into workflow-level environment variables.
• Keep the same package groups and the same jobs installing clang as before.
• Leave sanitizer job names, matrix shape, timeouts, triggers, and coverage unchanged.

Why

sanitized_ci.yml repeats the same long apt package lists across the Linux sanitizer jobs. Factoring those lists makes the workflow easier to review and prepares smaller follow-up refactors for the sanitizer CI without changing behavior.

Refs #27841.

Validation

• Parsed .github/workflows/sanitized_ci.yml with Ruby YAML.
• Confirmed folded YAML env values resolve to the original package strings.
• Ran git diff --check.
• Ran AI code review; no findings.

rtk prettier --check .github/workflows/sanitized_ci.yml could not run locally because Corepack fails with the known package signature/keyid error before invoking Prettier. Workflow Lint should validate formatting in CI.

[ulises-jeremias]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Another round soon, please!

Reviewed commit: 672f77e22a

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".