Add Retry to Flaky rand test

[zeotuan]

Proposed changes

• The rand test can be sometimes flaky so this PR aim to add some retry on AssertionError for rand test
• Fix lint issue introduced from More robust rand_laplace implementation #271 and enable linting on PR

Types of changes

• Bugfix (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)
• Documentation Update (if none of the other choices apply)

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[SemyonSinchenko]

LGTM