feat: add middleware for handling requests without cancel context

Introduced `GTagMiddlewarWithoutCancel` and `MPv2MiddlewarWithoutCancel` to allow handling of requests with contexts where cancellation signals are ignored. This improves flexibility for specific use cases where cancel propagation is not desired.

pkg/client/gtagmiddleware.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"context"
 	"net/http"
 	"strings"
 
@@ -58,6 +59,12 @@ func GTagMiddlewarClientID(next GTagHandler) GTagHandler {
 	}
 }
 
+func GTagMiddlewarWithoutCancel(next GTagHandler) GTagHandler {
+	return func(r *http.Request, payload *gtag.Payload) error {
+		return next(r.WithContext(context.WithoutCancel(r.Context())), payload)
+	}
+}
+
 func GTagMiddlewarSessionID(measurementID string) GTagMiddleware {
 	measurementID = strings.Split(measurementID, "-")[1]
 	return func(next GTagHandler) GTagHandler {

pkg/client/mpv2middleware.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"context"
 	"net/http"
 	"strings"
 
@@ -47,6 +48,12 @@ func MPv2MiddlewarDebugMode(next MPv2Handler) MPv2Handler {
 	}
 }
 
+func MPv2MiddlewarWithoutCancel(next MPv2Handler) MPv2Handler {
+	return func(r *http.Request, payload *mpv2.Payload[any]) error {
+		return next(r.WithContext(context.WithoutCancel(r.Context())), payload)
+	}
+}
+
 func MPv2MiddlewareUserID(cookieName string) MPv2Middleware {
 	return func(next MPv2Handler) MPv2Handler {
 		return func(r *http.Request, payload *mpv2.Payload[any]) error {