fix(test): Skip SIGTERM tests on Windows

[mildaniel]

Which issue(s) does this change fix?

N/A

Why is this change necessary?

Integration tests are failing on Windows since the SIGTERM signal isn't terminating the process.

How does it address the issue?

Skip these tests entirely since they're not relevant for Windows.

What side effects does this change have?

N/A

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.