go.mod: update k8s deps to v0.26.2 (remove "replace" rule)

Replace rules are not inherited by consumers of buildx as a module, and as
such would default to use the v0.26.2 version. Removing the replace rules
also removes various (indirect) dependencies (although brings in some new
packages from k8s itself).

The "azure" and "gcp" authentication packages in k8s.io/go-client are now
no longer functional, so removing those imports.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/k8s.io/client-go/tools/remotecommand/v1.go

@@ -19,7 +19,6 @@ package remotecommand
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	"k8s.io/api/core/v1"
@@ -29,8 +28,8 @@ import (
 
 // streamProtocolV1 implements the first version of the streaming exec & attach
 // protocol. This version has some bugs, such as not being able to detect when
-// non-interactive stdin data has ended. See http://issues.k8s.io/13394 and
-// http://issues.k8s.io/13395 for more details.
+// non-interactive stdin data has ended. See https://issues.k8s.io/13394 and
+// https://issues.k8s.io/13395 for more details.
 type streamProtocolV1 struct {
 	StreamOptions
 
@@ -111,7 +110,7 @@ func (p *streamProtocolV1) stream(conn streamCreator) error {
 
 	// always read from errorStream
 	go func() {
-		message, err := ioutil.ReadAll(p.errorStream)
+		message, err := io.ReadAll(p.errorStream)
 		if err != nil && err != io.EOF {
 			errorChan <- fmt.Errorf("Error reading from error stream: %s", err)
 			return