Update module github.com/prometheus/client_golang to v1.15.1

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/go-test/deep v1.1.0
 	github.com/patrickmn/go-cache v0.0.0-20180815053127-5633e0862627
 	github.com/pquerna/otp v1.4.0
-	github.com/prometheus/client_golang v1.12.2
+	github.com/prometheus/client_golang v1.15.1
 	github.com/sethvargo/go-password v0.2.0
 	github.com/tv42/zbase32 v0.0.0-20220222190657-f76a9fc892fa
 	golang.org/x/crypto v0.0.0-20220829220503-c86fa9a7ed90