Use SHA256 fingerprint instead of MD5 for LFS token secret

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/355878

**Problem**

FIPS restricted environments don't support MD5 fingerprints. LFS
secrets based on MD5 fingerpritn won't work there.

**Solution**

Use SHA256 fingerprint as a base for secret generation.

Changelog: changed

lib/gitlab/lfs_token.rb

@@ -99,7 +99,7 @@ module Gitlab
         case actor
         when DeployKey, Key
           # Since fingerprint is based on the public key, let's take more bytes from attr_encrypted_db_key_base
-          actor.fingerprint.delete(':').first(16) + Settings.attr_encrypted_db_key_base_32
+          actor.fingerprint_sha256.first(16) + Settings.attr_encrypted_db_key_base_32
         when User
           # Take the last 16 characters as they're more unique than the first 16
           actor.id.to_s + actor.encrypted_password.last(16) + Settings.attr_encrypted_db_key_base.first(16)