chore(ci): pin dd-sts-action to SHA.

[Zenithar]

What does this PR do?

• Adds new functionality
• Alters existing functionality
• Fixes a bug
• Improves documentation or testing

Please briefly describe your changes as well as the motivation behind them:

• Pin the dd-sts-action by SHA

Code Quality Checklist

• The documentation is up to date.
• My code is sufficiently commented and passes continuous integration checks.
• I have signed my commit (see Contributing Docs).

Testing

• I leveraged continuous integration testing
  • by depending on existing unit tests or end-to-end tests.
  • by adding new unit tests or end-to-end tests.
• I manually tested the following steps:
  • x
  • locally.
  • as a canary deployment to a cluster.

[datadog-datadog-prod-us1]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 38.49% (+0.02%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 272a3d2 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}