chore: Fix testifylint errors in middleware

[nickajacks1]

Description

Update various assertions in the middleware packages to match testify best practices in preparation for an upcoming update to golangci-lint. For float comparisons, an epsilon of 0.1% was chosen somewhat arbitrarily.

https://github.com/Antonboom/testifylint

Type of Change

• Code consistency (non-breaking change which improves code reliability and robustness)

Checklist

• Conducted a self-review of the code and provided comments for complex or critical parts.
• Added or updated unit tests to validate the effectiveness of the changes or new features.
• Ensured that new and existing unit tests pass locally with the changes.
• Verified that any new dependencies are essential and have been agreed upon by the maintainers/community.

[gaby]

Lgtm

[ReneWerner87]

Thx

[efectn]

We should enable testifylint on golangci-lint golangci/golangci-lint#4103

[gaby]

We should enable testifylint on golangci-lint golangci/golangci-lint#4103

It requires updating golanci-lint first. But yes, makes sense