docs: password-strength meter has been dropped (#2041)

docs/docs/concepts/security.mdx

@@ -316,15 +316,6 @@ Passwords must be checked against a database of compromised secrets such as
 > reason for rejection, and SHALL require the subscriber to choose a different
 > value.
 
-Show the user a password-strength meter (to be implemented, see
-[#136](https://github.com/ory/kratos/issues/136)):
-
-> Verifiers SHOULD offer guidance to the subscriber, such as a password-strength
-> meter [Meters], to assist the user in choosing a strong memorized secret. This
-> is particularly important following the rejection of a memorized secret on the
-> above list as it discourages trivial modification of listed (and likely very
-> weak) memorized secrets
-
 Do not require mixtures of characters types or prohibiting repeated characters:
 
 > Verifiers SHOULD NOT impose other composition rules (e.g., requiring mixtures