feat: enable FIPS 140-3 auto-detection via //go:debug directive

When built with GOFIPS140=certified (or latest), Go embeds fips140=on
in DefaultGODEBUG, making FIPS always active. The //go:debug fips140=auto
directive overrides this default so the binary reads
/proc/sys/crypto/fips_enabled at startup and activates FIPS only when
the host system is in FIPS mode.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: martinszuc

cmd/helm/helm.go

@@ -16,6 +16,8 @@ limitations under the License.
 
 package main // import "helm.sh/helm/v4/cmd/helm"
 
+//go:debug fips140=auto
+
 import (
 	"errors"
 	"log/slog"