[nix] add logs to console while waiting for MariaDB to come up

Summary:
My nix environment got messed up when my laptop updated MacOS. @atul and I spent pretty much all day troubleshooting and at different points of the investigation were led astray since this sleep in this while loop hangs w/o giving any info to the dev. The actual issue was related to a DB corruption issue which required me to nuke my db and start from scratch. While this diff does not solve the underlying issue we hope that at the very least these logs might give any future devs who run into this issue a better idea of where to look.

In this Linear comment, @ashoat @atul and I discuss adding this log

Only in the case that issues are occurring. There's a sleep in a while loop when things are in the broken state, so it just hangs without giving the developer any useful information. If instead we did something loosely like echo "waiting for MariaDB Socket" && sleep 1 it might give the developer an idea of where to look.

Linear issue: https://linear.app/comm/issue/ENG-4980/ginsu-nix-issues

Test Plan: n/a

Reviewers: O1 Nix, atul, varun, bartek, ashoat

Reviewed By: O1 Nix, atul, varun, ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D9223