fix: remove deprecated function tempfile.mktemp

[xiaoj655]

No description provided.

[Copilot]

Pull request overview

Updates the blue-krill SDK test utilities to avoid insecure temp-file creation patterns and aligns the dev test stack with a newer pytest version.

Changes:

• Replace tempfile.mktemp() usage in the storages test fixture with NamedTemporaryFile(..., delete=False) to generate temp paths/files.
• Bump pytest dev dependency to >=7,<8.
• Regenerate poetry.lock to reflect the updated dependency set.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
sdks/blue-krill/tests/storages/conftest.py	Updates the mktemp fixture implementation to avoid tempfile.mktemp().
sdks/blue-krill/pyproject.toml	Updates pytest version constraint for dev dependencies.
sdks/blue-krill/poetry.lock	Lockfile regeneration after dependency updates (now indicates Poetry 2.2.1).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.