fix(common): remove testing package import from production code

The testing package was imported in capabilities.go only to call
testing.Testing() for detecting test builds. This pulls the testing
package into production binaries.

Replace with build-tag-based approach: isTestBuild is true when built
with -tags test and false otherwise.

Signed-off-by: BillionClaw <billionclaw+clawoss@users.noreply.github.com>

pkg/chart/common/capabilities.go

@@ -20,7 +20,6 @@ import (
 	"slices"
 	"strconv"
 	"strings"
-	"testing"
 
 	"github.com/Masterminds/semver/v3"
 	"k8s.io/client-go/kubernetes/scheme"
@@ -146,7 +145,7 @@ func makeDefaultCapabilities() (*Capabilities, error) {
 	// Test builds don't include debug info / module info
 	// (And even if they did, we probably want stable capabilities for tests anyway)
 	// Return a default value for test builds
-	if testing.Testing() {
+	if isTestBuild {
 		return newCapabilities(kubeVersionMajorTesting, kubeVersionMinorTesting)
 	}
 

pkg/chart/common/capabilities_prod.go

@@ -0,0 +1,20 @@
+//go:build !test
+
+/*
+Copyright The Helm Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package common
+
+const isTestBuild = false

pkg/chart/common/capabilities_testbuild.go

@@ -0,0 +1,20 @@
+//go:build test
+
+/*
+Copyright The Helm Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package common
+
+const isTestBuild = true