replace interface{} → any

[n9te9]

What

replaced interface{} to any.

Why

golang 1.18 support any as type alias for interafce{}. If echo follow golang support policy, the smarter using any than using interface{}.

Concerns

Impact for an application run the environment that golang version is < golang 1.18. The application run at environment is under golang 1.18 will be failed to run, since type alias any is supported after golang 1.18. If echo support the application run at environment is under golang 1.18, this PR should be contained to v5.

[luckycatx]

@aldas Maybe check this PR