SCA: Implement feature flag for versioned shlib depends

Let's err on the side of caution and only enable versioned shared
library dependencies if the environment variable
MELANGE_VERSIONED_SHLIB_DEPENDS is non-empty.

Signed-off-by: Sergio Durigan Junior <[email protected]>

Author: sergiodj

pkg/sca/sca.go

@@ -24,6 +24,7 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
+	"os"
 	"path/filepath"
 	"slices"
 	"strings"
@@ -298,6 +299,11 @@ func dereferenceCrossPackageSymlink(hdl SCAHandle, path string, extraLibDirs []s
 func determineShlibVersion(ctx context.Context, hdl SCAHandle, shlib string) (string, error) {
 	log := clog.FromContext(ctx)
 
+	// Feature flag to disable versioned shlib dependencies.
+	if os.Getenv("MELANGE_VERSIONED_SHLIB_DEPENDS") == "" {
+		return "", nil
+	}
+
 	if hdl.Options().NoVersionedShlibDeps {
 		// This package does not care about versioned shlib
 		// depends.