fix(fires): report a 00:45 UTC detection as 00:45, not "45"

get_active_fires joined FIRMS acq_date and the unpadded acq_time, so a
detection at 00:45 UTC came back as "2026-01-01 45". The row now uses
acquisitionMsUtc, which pads the time, and reports an ISO UTC timestamp
like the other tool times.

changelog.d/1395-fires-tool-acquired-time.md

@@ -0,0 +1,4 @@
+- Report a fire detection's acquisition time as a UTC timestamp in
+  `get_active_fires`. The tool joined FIRMS's unpadded date and time, so a
+  00:45 UTC detection read "2026-01-01 45"; it now reads
+  `2026-01-01T00:45:00.000Z` (Rudy Celekli, @rudycelekli, #1395).