fix: deprecated call types & fixture bug

[begumcig]

Description

Fixes issues with the sharpness and memory metric tests in the nightlies.

Sharpness test: was failing because it was still using a deprecated call_type that got removed in the latest version. Updated the test to use the correct call.

Memory metric tests: these pass locally but fail in the nightlies. Switched the fixture to sd_tiny to check if the failures are fixture-related. This should help us narrow down whether the memory metric issue comes from the flux_tiny fixture specifically, or from something else (e.g. dependency or repo changes).

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes