fix: use a single translator for middleware (#10633)

# Which Problems Are Solved

Comparing the v3 and v4 deployments we noticed an increase in memory
usage. A first analysis revealed that it might be related to the
(multiple) initialization of the `i18n.Translator`, partially related

# How the Problems Are Solved

Initialize the tranlator once (apart from the translator interceptor,
which uses context / request specific information) and pass it to all
necessary middleware.

# Additional Changes

Removed unnecessary error return parameter from the translator
initialization.

# Additional Context

- noticed internally
- backport to v4.x

internal/api/http/middleware/instance_interceptor.go

@@ -8,7 +8,6 @@ import (
 	"strings"
 
 	"github.com/zitadel/logging"
-	"golang.org/x/text/language"
 
 	"github.com/zitadel/zitadel/internal/api/authz"
 	zitadel_http "github.com/zitadel/zitadel/internal/api/http"
@@ -24,12 +23,12 @@ type instanceInterceptor struct {
 	translator      *i18n.Translator
 }
 
-func InstanceInterceptor(verifier authz.InstanceVerifier, externalDomain string, ignoredPrefixes ...string) *instanceInterceptor {
+func InstanceInterceptor(verifier authz.InstanceVerifier, externalDomain string, translator *i18n.Translator, ignoredPrefixes ...string) *instanceInterceptor {
 	return &instanceInterceptor{
 		verifier:        verifier,
 		externalDomain:  externalDomain,
 		ignoredPrefixes: ignoredPrefixes,
-		translator:      newZitadelTranslator(),
+		translator:      translator,
 	}
 }
 
@@ -99,9 +98,3 @@ func setInstance(ctx context.Context, verifier authz.InstanceVerifier) (_ contex
 	span.End()
 	return authz.WithInstance(ctx, instance), nil
 }
-
-func newZitadelTranslator() *i18n.Translator {
-	translator, err := i18n.NewZitadelTranslator(language.English)
-	logging.OnError(err).Panic("unable to get translator")
-	return translator
-}