chore(deps): bump github.com/go-openapi/testify/v2

Bumps the go-openapi-dependencies group with 1 update: [github.com/go-openapi/testify/v2](https://github.com/go-openapi/testify).


Updates `github.com/go-openapi/testify/v2` from 2.0.2 to 2.1.8
- [Release notes](https://github.com/go-openapi/testify/releases)
- [Commits](go-openapi/testify@v2.0.2...v2.1.8)

---
updated-dependencies:
- dependency-name: github.com/go-openapi/testify/v2
  dependency-version: 2.1.8
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: go-openapi-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

go.mod

@@ -1,5 +1,5 @@
 module github.com/go-openapi/errors
 
-require github.com/go-openapi/testify/v2 v2.0.2
+require github.com/go-openapi/testify/v2 v2.1.8
 
 go 1.24.0

go.sum

@@ -1,2 +1,2 @@
-github.com/go-openapi/testify/v2 v2.0.2 h1:X999g3jeLcoY8qctY/c/Z8iBHTbwLz7R2WXd6Ub6wls=
-github.com/go-openapi/testify/v2 v2.0.2/go.mod h1:HCPmvFFnheKK2BuwSA0TbbdxJ3I16pjwMkYkP4Ywn54=
+github.com/go-openapi/testify/v2 v2.1.8 h1:Ctu3hazcJy+DzbCPKjA5S5JW86UFY9PZ2LAfuMp3Ru8=
+github.com/go-openapi/testify/v2 v2.1.8/go.mod h1:HCPmvFFnheKK2BuwSA0TbbdxJ3I16pjwMkYkP4Ywn54=