fix: unnecessary-format lint issues from merge

Signed-off-by: George Jenkins <gvjenkins@gmail.com>

internal/plugin/installer/installer.go

@@ -98,7 +98,7 @@ func InstallWithOptions(i Installer, opts Options) (*VerificationResult, error)
 
 		// Check if provenance data exists
 		if len(provData) == 0 {
-			return nil, fmt.Errorf("plugin verification failed: no provenance file (.prov) found")
+			return nil, errors.New("plugin verification failed: no provenance file (.prov) found")
 		}
 
 		// Provenance data exists - verify the plugin

internal/plugin/installer/verification_test.go

@@ -58,7 +58,7 @@ func TestInstallWithOptions_VerifyMissingProvenance(t *testing.T) {
 
 	// Plugin should NOT be installed
 	if _, err := os.Stat(installer.Path()); !os.IsNotExist(err) {
-		t.Errorf("Plugin should not be installed when verification fails due to missing .prov")
+		t.Error("Plugin should not be installed when verification fails due to missing .prov")
 	}
 }