[nix] upgrade mariadb from 10.8 to 10.11

Summary:
The modification of the flake.nix file is just removing the mariadb v.10.8 overlay, automatically bumping us to v.10.11.

The mariadb-up script is also modified to check whether or not an upgrade is necessary. If required, it will run `mariadb-upgrade`.

For a dev currently on 10.8, after this is landed, the dev will
1. pull the commit
2. exit their terminals and any `nix develop` sessions
3. pkill mariadb` if there is a running server process (`ps aux | grep mariadb`)
4. nix develop

On this nix develop, it should identify an upgrade is required and print out upgrade progress

After this step, everything should be upgraded

Depends on D12021

Test Plan:
- Set up dev environment with a mariadb 10.8 versioned table
- Launched an iOS simulator and exchanged messages between test users on a test community
- Ran through the above upgrade steps
- On a new iOS simulator, ensured that the messages were persisted from before and that new communities and users could be registered and exchange messages

Reviewers: ashoat, O1 Nix

Reviewed By: ashoat

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D12022

flake.nix

@@ -37,7 +37,6 @@
             (_: _: {
               emscripten = oldNixpkgs.emscripten; # Changed signficantly
               php80 = oldNixpkgs.php80; # Used for arcanist
-              mariadb = oldNixpkgs.mariadb_108;
             })
           ];
         };

nix/mariadb-up-mac.nix

@@ -121,6 +121,19 @@ in writeShellApplication {
       "${gnused}/bin/sed" -i -e "s|PASS|$PASS|g" "$KEYSERVER_DB_CONFIG"
     fi
 
+    # check if MariaDB requires an upgrade
+    "${lib.getBin mariadb}/bin/mariadb-upgrade" -u "$USER" \
+      --socket="$MYSQL_UNIX_PORT" \
+      --check-if-upgrade-is-needed >/dev/null 2>&1
+
+    exit_code=$?
+    if [[ $exit_code -eq 0 ]]; then
+      "${lib.getBin mariadb}/bin/mariadb-upgrade" -u "$USER" \
+        --socket="$MYSQL_UNIX_PORT" \
+
+      echo "Upgrade complete" >&2
+    fi
+
     # Explicitly exit this script so the parent shell can determine
     # when it's safe to return control of terminal to user
     exit 0