remove dependency to github.com/prometheus/client_golang in sigv4

Replace promhttp.RoundTripperFunc with local version.

Signed-off-by: Saeed Rasooli <saeed.gnu@gmail.com>

sigv4/go.mod

@@ -6,7 +6,6 @@ replace github.com/prometheus/common => ../
 
 require (
 	github.com/aws/aws-sdk-go v1.54.7
-	github.com/prometheus/client_golang v1.19.1
 	github.com/prometheus/common v0.53.0
 	github.com/stretchr/testify v1.9.0
 	gopkg.in/yaml.v2 v2.4.0
@@ -22,6 +21,7 @@ require (
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.19.1 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
 	golang.org/x/net v0.26.0 // indirect

sigv4/sigv4_test.go

@@ -23,10 +23,16 @@ import (
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/session"
 	signer "github.com/aws/aws-sdk-go/aws/signer/v4"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/stretchr/testify/require"
 )
 
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+// RoundTrip implements the RoundTripper interface.
+func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return rt(r)
+}
+
 func TestSigV4_Inferred_Region(t *testing.T) {
 	os.Setenv("AWS_ACCESS_KEY_ID", "secret")
 	os.Setenv("AWS_SECRET_ACCESS_KEY", "token")
@@ -50,7 +56,7 @@ func TestSigV4RoundTripper(t *testing.T) {
 
 	rt := &sigV4RoundTripper{
 		region: "us-east-2",
-		next: promhttp.RoundTripperFunc(func(req *http.Request) (*http.Response, error) {
+		next: RoundTripperFunc(func(req *http.Request) (*http.Response, error) {
 			gotReq = req
 			return &http.Response{StatusCode: http.StatusOK}, nil
 		}),