refactor: drop golang.org/x/exp dependency (#4940)

Go 1.21 added the new slices package upstream so we drop usage
of x/exp and use the stdlib package.

Author: kruskall

NOTICE.txt

@@ -12543,43 +12543,6 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
---------------------------------------------------------------------------------
-Dependency : golang.org/x/exp
-Version: v0.0.0-20240506185415-9bf2ced13842
-Licence type (autodetected): BSD-3-Clause
---------------------------------------------------------------------------------
-
-Contents of probable licence file $GOMODCACHE/golang.org/x/exp@v0.0.0-20240506185415-9bf2ced13842/LICENSE:
-
-Copyright (c) 2009 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
 --------------------------------------------------------------------------------
 Dependency : golang.org/x/lint
 Version: v0.0.0-20210508222113-6edffad5e616
@@ -45852,6 +45815,43 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 
 
+--------------------------------------------------------------------------------
+Dependency : golang.org/x/exp
+Version: v0.0.0-20240506185415-9bf2ced13842
+Licence type (autodetected): BSD-3-Clause
+--------------------------------------------------------------------------------
+
+Contents of probable licence file $GOMODCACHE/golang.org/x/exp@v0.0.0-20240506185415-9bf2ced13842/LICENSE:
+
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
 --------------------------------------------------------------------------------
 Dependency : golang.org/x/mod
 Version: v0.17.0

go.mod

@@ -75,7 +75,6 @@ require (
 	go.opentelemetry.io/collector/receiver/otlpreceiver v0.102.1
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.23.0
-	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
 	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616
 	golang.org/x/sync v0.7.0
 	golang.org/x/sys v0.20.0
@@ -280,6 +279,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.27.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.2.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
+	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 // indirect
 	golang.org/x/mod v0.17.0 // indirect
 	golang.org/x/net v0.25.0 // indirect
 	golang.org/x/oauth2 v0.20.0 // indirect

internal/pkg/agent/application/upgrade/artifact/config_test.go

@@ -6,12 +6,12 @@ package artifact
 
 import (
 	"reflect"
+	"slices"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"golang.org/x/exp/slices"
 
 	agentlibsconfig "github.com/elastic/elastic-agent-libs/config"
 	"github.com/elastic/elastic-agent-libs/transport/httpcommon"