Remove unused strconv import

Cascade fix from the web-UI edit that replaced strconv.Quote with
json.Marshal: the import was left in place, breaking compilation and
every downstream CI job (lint, tests, govulncheck x2, helm lint, e2e
lifecycle x3).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: ChrisJBurns

cmd/thv-operator/controllers/mcpauthzconfig_controller.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"strconv"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/errors"