Added logging for last_used_ip address count

Smriti Gargrequested to merge
smriti-log_last_used_ips_per_request into master

What does this MR do and why?

As per our findings in discussion here with Adam https://gitlab.slack.com/archives/C3NBYFJ6N/p1761826496971669 We understood that due to the table personal_access_token_last_used_ips high insert and delete rate, it is slowing down the endpoint /api/v4/personal_access_tokens/self response. With this MR we want to log the number of last_used_ips which are getting loaded per request to analyse the data and make sure our findings are correct. This endpoint needs to be optimized further.

This is for issue - https://gitlab.com/gitlab-org/gitlab/-/issues/569170

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