feat: add SkipMiddlewareOnNotFound to short-circuit 404/405 requests #2761

[its-ernest]

Fix for issue: #2761

This PR addresses #2761 by introducing SkipMiddlewareOnNotFound. This allows developers to avoid executing heavy global middleware (Auth, DB logging) for requests that result in a 404 or 405, improving performance and reducing log noise

Testing with below cmd saves 3 allocations.

go test -bench=BenchmarkMiddleware404 -benchmem

Sample output:

BenchmarkMiddleware404/Normal_404-8             {"time":"2026-03-04T22:00:36.5728429Z","level":"ERROR","msg":"failed to shut down server within given timeout","error":"context deadline exceeded"}
 1416462               890.7 ns/op           894 B/op         10 allocs/op
BenchmarkMiddleware404/Optimized_404-8           1000000              1472 ns/op             515 B/op          7 allocs/op
PASS
ok      github.com/labstack/echo/v5     6.217s

10-7 = 3 allocations saved for faster runtime

[its-ernest]

SkipMiddlewareOnNotFound runs router.Route before applyMiddleware, so global middleware (auth, rate limits) will not run on 404/405 when enabled; worth stating on the Echo field. nit: the comment above IsMethodNotAllowed says IsMethodAllowed and reads inverted.

Thanks for the catch. I have updated the comment for IsMethodNotAllowed and clarified the documentation for the SkipMiddlewareOnNotFound field